Acids Quiz
Uploaded by
wondimuAcids Quiz
Uploaded by
wondimuAcids Quiz #10 Review Answers
1. How many moles of Mg(OH)2 are required to neutralize 30.00 mL of 0.150 M
HCl?
A. 2.25 x 10-3 mol
B. 4.50 x 10-3 mol
C. 5.00 x 10-3 mol
D. 9.00 x 10-3 mol
2. The approximate Ka for the indicator phenolphthalein is
A. 6 x 10-19
B. 8 x 10-10
C. 6 x 10-8
D. 2 x 10-2
3. A new indicator, “B.C. Blue (HInd),” is red in bases and blue in acids. Describe
the shift in equilibrium and the resulting color change if 1.0 M HIO3 is added to a
neutral, purple solution of this indicator:
HInd + H2O ⇄ H3O+ + Ind-
A. Equilibrium shifts left, and colour becomes red
B Equilibrium shifts left, and colour becomes blue
C. Equilibrium shifts right, and colour becomes red
D. Equilibrium shifts right, and colour becomes blue
4. Which one of the following combinations would act as an acid buffer?
A. HCl and NaOH
B. KOH and KBr
C. NH3 and NH4Cl
D. CH3COOH and NaCH3COO
5. What is the pH at the transition point of an indicator if its Ka is 7.9 x 10-3?
A. 0.98
B. 2.10
C. 7.00
D. 11.90
6. Which of the following curves best represents the titration of sodium hydroxide
with hydrochloric acid?
A.
7. A student prepares a buffer by placing ammonium chloride in a solution of
ammonia. Equilibrium is established according to the equation:
NH3 + H2O ⇄ NH4+ + OH-
When a small amount of base is added to the buffer, the base reacts with
A. NH3 and the pH decreases
B. NH4+ and the pH decreases
C. NH3 to keep the pH relatively constant
D. NH4+ to keep the pH relatively constant
8. At the equivalence point in a titration involving 1.0 M solutions, which of the
following combinations would have the lowest conductivity?
A. Nitric acid and barium hydroxide
B. Acetic acid and sodium hydroxide
C. Sulphuric acid and barium hydroxide
D. Hydrochloric acid and sodium hydroxide
9. An indicator HInd produces a yellow colour in 0.1 M HCl solution and a red
colour in 0.1 M HCN solution. Therefore, the following equilibrium:
HCN + Ind- ⇄ HInd + CN-
A. Products are favored and the stronger acid is HInd
B. Products are favored and the stronger acid is HCN
C. Reactants are favored and the stronger acid is HInd
D. Reactants are favored and the stronger acid is HCN
10. The indicator methyl red is red in a solution of NaH2PO4. Which of the following
equations is consistent with this observation?
A. H2PO4- + H2O ⇄ HPO42- + H3O+
B. H2PO4- + H2O ⇄ H3PO4 + OH-
C. HPO42- + H2O ⇄ PO43- + H3O+
D. HPO42- + H2O ⇄ H2PO4- + OH-
11. Consider the following acid-base indicator equilibrium:
HInd(aq) + H2O(l) ⇄ H3O+(aq) ⇄ Ind-(aq)
Which of the following statements describes the conditions that exist in an
indicator equilibrium system at its transition point?
A. [HInd] = [Ind-]
B. [Ind-] = [H3O+]
C. [HInd] = [H3O+]
D. [H3O+] = [H2O]
12. Which of the following titrations would have an equivalence point less that pH 7?
A. NH3 and HCl
B. NaOH and HNO3
C. Ba(OH)2 and H2SO4
D. KOH and CH3COOH
13. Oxalic acid dihydrate is a pure, stable, crystalline substance. Which of the
following describes
one of its uses in acid-base titrations?
A. buffer
B. primary standard
C. indicator
D. acid anhydride
14. What is the complete ionic equation that describes the reaction of HCl(aq) with Pb(OH)2(s)?
A. H+(aq) + OH-(aq) ® H2O(l)
B. 2HCl(aq) + Pb(OH)2(s) ® PbCl2(s) + 2H2O(l)
C. 2H+(aq) + 2Cl-(aq) + Pb(OH)2(s) ® PbCl2(s) + 2H2O (l)
D. 2H+(aq) + 2Cl-(aq) + Pb2+(aq) + 2OH- ®Pb2+(aq) + 2Cl-(aq) + 2H2O (l)
15. What is the formula equation that describes the reaction of HCl(aq) with Pb(OH)2(s)?
A. H+(aq) + OH-(aq) ® H2O(l)
B. 2HCl(aq) + Pb(OH)2(s) ® PbCl2(s) + 2H2O(l)
C. 2H+(aq) + 2Cl-(aq) + Pb(OH)2(s) ® PbCl2(s) + 2H2O (l)
D. 2H+(aq) + 2Cl-(aq) + Pb2+(aq) + 2OH- ®Pb2+(aq) + 2Cl-(aq) + 2H2O (l)
16. What term is used to describe the point at which a chemical indicator changes
colour?
A. titration point
B. transition point
C. equivalence point
D. neutralization point
17. What term is used to describe the point in a titration where the acid has
completely reacted with the base.
A. titration point
B. transition point
C. equivalence point
D. neutralization point
18. Which of the following is a piece of equipment typically used in acid-base
titrations?
A. burette
B. cuvette
C. litmus paper
D. graduated cylinder
19. Identify an environmental problem associated with acid rain.
A. increasing the pH of lakes
B. the green house effect
C. chemical decomposition of rainwater
D. metals leeching from river rocks accumulating in lakes
20. A buffer solution is prepared using sufficient amounts of H2S and NaHS. What
limits this buffer’s effectiveness when NaOH is added?
A. [H2S]
B. [HS-]
C. [OH-]
D. [H3O+]
21. Which of the following is not a good use for an acid-base titration curve?
A. to determine the concentration of the acid
B. to select a suitable indicator for the titration
C. to determine whether the acid is strong or weak
D. to select a suitable primary standard for the titration
22. A substance which completely produces hydroxide ions in solution is a definition
of which of the following?
A. a strong Arrhenius acid
B. a strong Arrhenius base
C. a weak Arrhenius base
D. a strong Brønsted-Lowry base
23. When a strong acid is titrated with a strong base, what will the pH value be at the
equivalence point?
A. 0.0
B. 5.0
C. 7.0
D. 9.0
24. At a certain point in a strong acid-strong base titration, the moles of H+ are equal
to the moles of OH-. This is a definition of which of the following?
A. the end point
B. the titration point
C. the transition point
D. the equivalence point
25. A 25.0 mL sample of H2SO4(aq) is titrated with 15.5 mL of 0.50 M NaOH(aq).
What is the concentration of the H2SO4(aq) ?
A. 0.078 M
B. 0.16 M
C. 0.31 M
D. 0.62 M
26. When a weak acid is titrated with a strong base, what will the pH value be at the
equivalence point?
A. 0.0
B. 6.7
C. 7.0
D. 8.8
27. A substance which completely produces accepts a proton from an acid is a
definition of which of the following?
A. a strong Arrhenius acid
B. a strong Arrhenius base
C. a weak Arrhenius base
D. a strong Brønsted-Lowry base
28. Which of the following is a piece of equipment typically used in acid-base
titrations?
A. pipette
B. test tube
C. litmus paper
D. graduated cylinder
29. Water has the greatest tendency to act as an acid with which of the following?
A. NO3-
B. NO2-
C. H2PO4-
D. CH3COO-
30. Which net ionic equation best describes the reaction between NaOH and H2S?
A. H+(aq) + OH-(aq) ® H2O(l)
B. H2S(aq) + 2OH- ® 2H2O(l) + S2-(aq)
C. H2S(aq) + 2NaOH ® 2H2O(l) + Na2S(aq)
D. 2H+(aq) + S2-(aq) + 2NaOH(aq) ® 2H2O(l) + 2Na+(aq) + S2-(aq)
Acids Quiz #10 Review Answers
1. How many moles of Mg(OH)2 are required to neutralize 30.00 mL of 0.150 M
HCl?
A. 2.25 x 10-3 mol
B. 4.50 x 10-3 mol
C. 5.00 x 10-3 mol
D. 9.00 x 10-3 mol
2. The approximate Ka for the indicator phenolphthalein is
A. 6 x 10-19
B. 8 x 10-10
C. 6 x 10-8
D. 2 x 10-2
3. A new indicator, “B.C. Blue (HInd),” is red in bases and blue in acids. Describe
the shift in equilibrium and the resulting color change if 1.0 M HIO3 is added to a
neutral, purple solution of this indicator:
HInd + H2O ⇄ H3O+ + Ind-
A. Equilibrium shifts left, and colour becomes red
B Equilibrium shifts left, and colour becomes blue
C. Equilibrium shifts right, and colour becomes red
D. Equilibrium shifts right, and colour becomes blue
4. Which one of the following combinations would act as an acid buffer?
A. HCl and NaOH
B. KOH and KBr
C. NH3 and NH4Cl
D. CH3COOH and NaCH3COO
5. What is the pH at the transition point of an indicator if its Ka is 7.9 x 10-3?
A. 0.98
B. 2.10
C. 7.00
D. 11.90
6. Which of the following curves best represents the titration of sodium hydroxide
with hydrochloric acid?
A.
7. A student prepares a buffer by placing ammonium chloride in a solution of
ammonia. Equilibrium is established according to the equation:
NH3 + H2O ⇄ NH4+ + OH-
When a small amount of base is added to the buffer, the base reacts with
A. NH3 and the pH decreases
B. NH4+ and the pH decreases
C. NH3 to keep the pH relatively constant
D. NH4+ to keep the pH relatively constant
8. At the equivalence point in a titration involving 1.0 M solutions, which of the
following combinations would have the lowest conductivity?
A. Nitric acid and barium hydroxide
B. Acetic acid and sodium hydroxide
C. Sulphuric acid and barium hydroxide
D. Hydrochloric acid and sodium hydroxide
9. An indicator HInd produces a yellow colour in 0.1 M HCl solution and a red
colour in 0.1 M HCN solution. Therefore, the following equilibrium:
HCN + Ind- ⇄ HInd + CN-
A. Products are favored and the stronger acid is HInd
B. Products are favored and the stronger acid is HCN
C. Reactants are favored and the stronger acid is HInd
D. Reactants are favored and the stronger acid is HCN
10. The indicator methyl red is red in a solution of NaH2PO4. Which of the following
equations is consistent with this observation?
A. H2PO4- + H2O ⇄ HPO42- + H3O+
B. H2PO4- + H2O ⇄ H3PO4 + OH-
C. HPO42- + H2O ⇄ PO43- + H3O+
D. HPO42- + H2O ⇄ H2PO4- + OH-
11. Consider the following acid-base indicator equilibrium:
HInd(aq) + H2O(l) ⇄ H3O+(aq) ⇄ Ind-(aq)
Which of the following statements describes the conditions that exist in an
indicator equilibrium system at its transition point?
A. [HInd] = [Ind-]
B. [Ind-] = [H3O+]
C. [HInd] = [H3O+]
D. [H3O+] = [H2O]
12. Which of the following titrations would have an equivalence point less that pH 7?
A. NH3 and HCl
B. NaOH and HNO3
C. Ba(OH)2 and H2SO4
D. KOH and CH3COOH
13. Oxalic acid dihydrate is a pure, stable, crystalline substance.
Which of the following describes one of its uses in acid-base titrations?
A. buffer
B. primary standard
C. indicator
D. acid anhydride
14. What is the complete ionic equation that describes the reaction of HCl(aq) with Pb(OH)2(s)?
A. H+(aq) + OH-(aq) ® H2O(l)
B. 2HCl(aq) + Pb(OH)2(s) ® PbCl2(s) + 2H2O(l)
C. 2H+(aq) + 2Cl-(aq) + Pb(OH)2(s) ® PbCl2(s) + 2H2O (l)
D. 2H+(aq) + 2Cl-(aq) + Pb2+(aq) + 2OH- ®Pb2+(aq) + 2Cl-(aq) + 2H2O (l)
15. What is the formula equation that describes the reaction of HCl(aq) with Pb(OH)2(s)?
A. H+(aq) + OH-(aq) ® H2O(l)
B. 2HCl(aq) + Pb(OH)2(s) ® PbCl2(s) + 2H2O(l)
C. 2H+(aq) + 2Cl-(aq) + Pb(OH)2(s) ® PbCl2(s) + 2H2O (l)
D. 2H+(aq) + 2Cl-(aq) + Pb2+(aq) + 2OH- ®Pb2+(aq) + 2Cl-(aq) + 2H2O (l)
16. What term is used to describe the point at which a chemical indicator changes
colour?
A. titration point
B. transition point
C. equivalence point
D. neutralization point
17. What term is used to describe the point in a titration where the acid has
completely reacted with the base.
A. titration point
B. transition point
C. equivalence point
D. neutralization point
18. Which of the following is a piece of equipment typically used in acid-base
titrations?
A. burette
B. cuvette
C. litmus paper
D. graduated cylinder
19. Identify an environmental problem associated with acid rain.
A. increasing the pH of lakes
B. the green house effect
C. chemical decomposition of rainwater
D. metals leeching from river rocks accumulating in lakes
20. A buffer solution is prepared using sufficient amounts of H2S and NaHS. What
limits this buffer’s effectiveness when NaOH is added?
A. [H2S]
B. [HS-]
C. [OH-]
D. [H3O+]
21. Which of the following is not a good use for an acid-base titration curve?
A. to determine the concentration of the acid
B. to select a suitable indicator for the titration
C. to determine whether the acid is strong or weak
D. to select a suitable primary standard for the titration
22. A substance which completely produces hydroxide ions in solution is a definition
of which of the following?
A. a strong Arrhenius acid
B. a strong Arrhenius base
C. a weak Arrhenius base
D. a strong Brønsted-Lowry base
23. When a strong acid is titrated with a strong base, what will the pH value be at the
equivalence point?
A. 0.0
B. 5.0
C. 7.0
D. 9.0
24. At a certain point in a strong acid-strong base titration, the moles of H+ are equal
to the moles of OH-. This is a definition of which of the following?
A. the end point
B. the titration point
C. the transition point
D. the equivalence point
25. A 25.0 mL sample of H2SO4(aq) is titrated with 15.5 mL of 0.50 M NaOH(aq).
What is the concentration of the H2SO4(aq) ?
A. 0.078 M
B. 0.16 M
C. 0.31 M
D. 0.62 M
26. When a weak acid is titrated with a strong base, what will the pH value be at the
equivalence point?
A. 0.0
B. 6.7
C. 7.0
D. 8.8
27. A substance which completely produces accepts a proton from an acid is a
definition of which of the following?
A. a strong Arrhenius acid
B. a strong Arrhenius base
C. a weak Arrhenius base
D. a strong Brønsted-Lowry base
28. Which of the following is a piece of equipment typically used in acid-base
titrations?
A. pipette
B. test tube
C. litmus paper
D. graduated cylinder
29. Water has the greatest tendency to act as an acid with which of the following?
A. NO3-
B. NO2-
C. H2PO4-
D. CH3COO-
30. Which net ionic equation best describes the reaction between NaOH and H2S?
A. H+(aq) + OH-(aq) ® H2O(l)
B. H2S(aq) + 2OH- ® 2H2O(l) + S2-(aq)
C. H2S(aq) + 2NaOH ® 2H2O(l) + Na2S(aq)
D. 2H+(aq) + S2-(aq) + 2NaOH(aq) ® 2H2O(l) + 2Na+(aq) + S2-(aq)
Kinetics Quiz #5 Mechanisms Answers
1. Consider the following reaction mechanism
Step 1: M + X → MX
Step 2: MX + A → D + X
The chemical species MX is a(n)
A. Catalyst
B. Inhibitor
C. Final Product
D. Reaction Intermediate
2. Consider the following reaction mechanism
Step 1: NO2 + NO2 → NO + NO3
Step 2: NO3 + CO → NO2 + CO2
The overall reaction is
A. 2NO2 → NO3 + NO
B. NO2 + CO → NO + CO2
C. NO3 + CO → NO2 + CO2
D. NO2 + NO3 + CO → NO3 + NO2 + NO + CO2
3. Consider the following reaction mechanism
Step 1: V3+ + Cu2+ → V4+ + Cu+ (slow)
Step 2: Cu+ + Fe3+ → Cu2+ + Fe2+ (fast)
The reaction intermediate is
A. Cu+
B. Cu2+
C. V3+
D. Fe3+
4. Consider the following reaction Mechanism
Step 1: H2O2 + I - → H2O + IO-
Step 2: H2O2 + IO - → H2O + O2 + I -
The reaction intermediate is
A. I-
B. IO -
C. H2O
D. H2O2
5. Consider the following potential energy diagram
The above potential energy diagram represents an
A. Exothermic reaction involving one step
B. Exothermic reaction involving two steps
C. Endothermic reaction involving one step
D. Endothermic reaction involving two steps
6. Consider the following reaction mechanism
Step 1: NO2(g) + NO2(g) → NO(g) + NO3(g) (slow)
Step 2: NO3(g) + CO(g) → CO2(g) + NO2(g) (fast)
Which one of the following changes would result in the greatest increase in reaction rate
A. Increase [CO]
B. Decrease [NO]
C. Increase [NO2]
D. Increase [NO3]
7. An uncatalyzed reaction was found to produce 40 kJ of energy in 10 mins. When catalyzed,
the same reaction produced 40 kJ of energy in 2 mins. Which one of the following potential
energy diagrams is consistent with the above data?
8. Consider the following reaction mechanism
Step 1: ICl + H2 → HI + HCl (slow)
Step 2: ICl + HI → HCl + I2 (fast)
The Species HCl is a
A. Product
B. Catalyst
C. Reactant
D. Reaction Intermediate
9. Consider the following reaction mechanism
Step 1: Cl(g) + O3(g) → ClO(g) + O2(g)
Step 2: O(g) + ClO(g) → Cl(g) + O2(g)
The Reaction intermediate is
A. Cl
B. O2
C. O3
D. ClO
10. In a reaction mechanism, the rate determining step is the
A. Fastest and has the lowest reaction rate.
B. Fastest and has the highest activation energy
C. Slowest and has the lowest activation energy
D. Slowest and has the highest activation energy
11. Select the true statement concerning the above potential energy diagram.
A. The catalyzed reaction has a larger ∆H
B. The uncatalyzed reaction has a larger ∆H
C. The catalyzed reaction has a greater rate of reaction
D. The uncatalyzed reaction has a greater rate of reaction
12. Which point on the diagram above represents the potential energy of the activated complex
formed in the uncatalyzed reaction?
A. I
B. II
C. III
D. IV
13. Consider the following reaction
Step 1: NO(g) + O3(g) ------ > NO2(g) + O2(g)
Step 2: O(g) + NO2(g) ------ > NO(g) + O2(g)
The catalyst is
A. O2
B. O3
C. NO
D. NO2
14. Consider the following reaction mechanism
Step 1: N2O(g) ------ > N2(g) + O(g)
Step 2: N2O(g) + O(g) ------ > N2(g) + O2(g)
The reactant in the overall reaction is
A. O
B. O2
C. N2
D. N2O
15. Consider the following reaction
O3(g) + NO(g) ----- > NO2(g) + O2(g)
NO2(g) + O(g) ------ > NO(g) + O2(g)
The product in the overall reaction is
A. O2
B. O3
C. NO
D. NO2
Use the following reaction mechanism to answer questions 16 and 17.
Step 1: 2PO → P2O2 (fast)
Step 2: P2O2 + H2 → P2O + H2O (slow)
Step 3: P2O + H2 → P2 + H2O (fast)
16. Increasing the concentration of which of the following substances would cause the
greatest increase in the reaction rate?
A. H2
B. PO
C. P2O
D. H2O
17. Which of the following are products in the overall reaction?
I P2
II P2O2
III PO2
IV H2O
A. I and II only
B. I and IV only
C. II and III only
D. III and IV only
18. The Intermediates are:
A. NO H2
B. H2O P2
C. P2O2 PO
D. P2O2 P2O
19. Which of the following could describe a catalyst?
A. A substance that increases the reaction time.
B. A substance that provides an alternate mechanism with higher activation energy.
C. A substance that is formed in one step and used up in a subsequent step in a
reaction mechanism.
D. A substance that is used up in one step and reformed in a subsequent step in
a reaction mechanism.
20. Consider the following reaction: 2PO(g) + O2(g) → 2PO2(g)
Why would this reaction probably involve more than one step?
A. There is insufficient activation energy.
B. This reaction has high activation energy.
C. Reactions between gases are typically slow.
D. A successful collision between three molecules is unlikely.
21. Consider the following reaction mechanism:
Step 1 Cl3 → Cl2 + Cl
Step 2 Cl3 + Cl → 2Cl2
Which of the following could represent the activated complex for Step 2?
A. Cl
B. Cl2
C. Cl3
D. Cl4
22. Consider the reaction: 2C4H10(g) + 13O2(g) → 8CO2(g) + 10H2O(l)
Which of the following explains, in terms of collision theory, why this reaction occurs in
more than one step?
A. a low C4H12(g) pressure
B. low temperature of reactant mixture
C. low probability of a multi-particle collision
D. particles collide with insufficient kinetic energy
23. Consider the following reaction mechanism and overall reaction:
Step 1 ½ O2(g) + NO(g) → NO2(g)
sunlight
Step 2 NO2(g) → NO(g) + O(g)
Step 3 O2(g) + O(g) → O3(g)
Overall 3/2 O2 (g) → O3(g)
What is the catalyst in this mechanism?
A. O
B. NO
C. NO2
D. sunlight
24. What is an intermediate in this mechanism?
A. O
B. NO
C. O3
D. sunlight
25. Consider the following reaction mechanism:
Step 1 NOI → NO + I
Step 2 NOI + I → NOI2
Identify the reaction intermediate.
A. I
B. NOI2
C. NO
D. NOI
26. Consider the following reaction mechanism:
Step 1 2NO2 → NO3 + NO
Step 2 NO3 + CO → NO2 + CO2
Identify a product in the overall reaction.
A. CO
B. CO2
C. NO2
D. NO3
27. Consider the following reaction mechanism:
Step 1 2NO2 → NO3 + NO
Step 2 NO3 + CO → NO2 + CO2
Identify an intermediate.
A. CO
B. CO2
C. NO2
D. NO3
Solubility Quiz #7 Common Ion Effect
1. Consider the following equilibrium: CaCO3(s) ⇄ Ca2+(aq) +CO32-(aq)
Which of the following reagents, when added to the equilibrium system, would cause
more CaCO3 to dissolve?
A. KNO3(s)
B. CaCO3(s)
C. H2C2O4(s)
D. Na2CO3(s)
2. A solution contains a mixture of SO42- and S2-. Which of the following cations could be
used to remove only the SO42- from the solution by precipitation?
A. K+
B. Sr2+
C. Pb2+
D. Cu2+
3. Consider the following solubility equilibrium: MgCO3(s)⇄ Mg2+(aq) + CO32-(aq)
The addition of which of the following substances would decrease the solubility of
MgCO3?
A. H2O
B. NaCl
C. NaOH
D. Na2CO3
4. A student could precipitate silver chloride from a saturated solution of silver chloride by
adding
A. water
B. sodium iodide
C. sodium nitrate
D. sodium chloride
5. The greatest mass of solid SnS will dissolve in 1.0 L of
A. H2O
B. 0.10 M MgS
C. 0.10 M (NH4)2S
D. 0.10 M Sn(NO3)2
6. Magnesium carbonate would be the most soluble in a solution of
A. MgCl2
B. NaNO3
C. Na2CO3
D. Mg(NO3)2
7. Sodium iodide is added to a saturated solution of lead (II) iodide. The net change is
A. [I-] increases and [Pb2+] increases
B. [I-] decreases and [Pb2+] decreases
C. [I-] increases and [Pb2+] decreases
D. [I-] decreases and [Pb2+] increases
8. Consider the following equilibrium: Pbl2(s) + heat ⇄ Pb2+(aq) + 2I-(aq)
Which of the following changes would result in more Pbl2 dissolving?
A. Adding more Pbl2
B. Increasing the pressure
C. Adding some Pb(NO3)2
D. Increasing the temperature
9. Consider the following equilibrium: AgCl(s) ⇄ Ag+(aq) + Cl-(aq)
Sodium chloride is added to a saturated solution of AgCl. The amount of solid AgCl will
A. increase as the equilibrium shifts to the left
B. decrease as the equilibrium shifts to the left
C. increase as the equilibrium shifts to the right
D. decrease as the equilibrium shifts to the right
10. Consider the following equilibrium: NH4Cl(s) + energy ⇄ NH+4(aq) + Cl-(aq)
Which of the following will increase the solubility of ammonium chloride?
A. Stirring the solution
B. Adding more water
C. Adding more NH4Cl(s)
D. Increasing the temperature
11. Which of the following substances will have the least effect on the equilibrium in a
saturated solution of PbBr2(s)?
A. HI
B. Na2S
C. KNO3
D. Pb(NO3)2
12. Which of the following substances will have the greatest effect on the equilibrium in a
saturated solution of PbBr2(s)?
A. 1.0 M Pb(NO3)2
B. 1.0 MNaBr
C. 1.0 M CaBr2
D. 1.0 M AlBr3
13. Which compound will have the lowest solubility?
A. BeS
B. FeS
C. ZnS
D. Cs2S
14. Which compound will have the highest solubility?
A. CuS
B. FeS
C. ZnS
D. Cs2S
15. Which anion would be most effective in removing the cations (Mg2+ and Ca2+) that are
responsible for hard water?
A. S2-
B. Cl-
C. PO43-
D. SO42-
16. Which of the following ions could be used in the lowest concentration to remove Ag+
ions from a polluted water sample?
A. I-
B. Br-
C. BrO3-
D. CO32-
17. What will be the effect of adding some solid AgNO3 to a saturated solution of AgCl ?
A. The AgNO3 will not dissolve.
B. More solid AgCl will dissolve.
C. More solid AgCl will be produced.
D. There will be no effect on AgCl equilibrium.
18. An experiment is conducted to identify an unknown cation that is present in each of four
beakers.
The following chemicals are added to an unknown solution containing one cation.
RbNO3 (NH4)2S MnSO4 Na2CO3
no ppt ppt no ppt ppt
Which of the following could be the unknown cation?
A. Ag+
B. Fe3+
C. Ba2+
D. Be2+
19. An equal number of moles of Na2CO3 is added to four different 100.mL samples.
Sample 1 Sample 2 Sample 3 Sample 4
0.50 M Ba2+ 0.50 M Ca 2+ 0.50 M Mg2+ 0.50 M Sr2+
A precipitate forms in only one of the samples. Identify the cation which is present
in the precipitate.
A. Ba2+
B. Ca2+
C. Mg2+
D. Sr2+
20. An equal number of moles of Na2CO3 is added to four different samples that contain the
cations below in low concentration.
Sample 1 Sample 2 Sample 3 Sample 4
Ba2+ Ca2+ Mg2+ Sr2+
A precipitate forms in three of the samples. Identify the cation which is present in
sample that does not precipitate.
A. Ba2+
B. Ca2+
C. Mg2+
D. Sr2+
21. Consider the following equilibrium: Mg(OH)2(s) ⇌ Mg2+ + 2OH-
Adding which of the following would cause the solid to dissolve?
A. HCl
B. KOH
C. Mg(OH)2
D. Mg(NO3)2
22. Consider the following equilibrium: Mg(OH)2(s) ⇌ Mg2+ + 2OH-
Adding which of the following would cause the most solid to precipitate?
A. 1.0MHCl
B. 1.0MKOH
C. 1.0MSr(OH)2
D. 1.0MMg(NO3)2
23. When equal volumes of 0.40 M Ca(NO3)2 and 0.40 M Na2SO4are mixed together,
A. a precipitate forms and the Trial Ksp would be less than Ksp.
B. no precipitate forms and the Trial Ksp would be less than Ksp.
C. a precipitate forms and the Trial Ksp would be greater than Ksp.
D. no precipitate forms and the Trial Ksp would be greater than Ksp.
24. When equal volumes of 0.002 M Ca(NO3)2 and 0.002 M Na2SO4are mixed
together,
A. a precipitate forms and the Trial Ksp is less than Ksp.
B. no precipitate forms and the Trial Ksp is less than Ksp.
C. a precipitate forms and the Trial Ksp is greater than Ksp.
D. no precipitate forms and the Trial Ksp is greater than Ksp.
25. When equal volumes of 0.02 M Ca(NO3)2 and 0.02 M Na2SO4are mixed together,
A. a precipitate forms and the Trial Ksp is less than Ksp.
B. no precipitate forms and the Trial Ksp is less than Ksp.
C. a precipitate forms and the Trial Ksp is greater than Ksp.
D. no precipitate forms and the Trial Ksp is greater than Ksp.
26. Which of the following is commonly used to describe the solubility of a compound?
A. mass of solute / moles of solute
B. moles of solution / mass of solute
C. mass of solute / volume of solution
D. mass of solution / volume of solute
Redox Quiz #1 Agents, Spontaneous Reactions, Oxidation #.
1. In a redox reaction, the species that loses electrons
A. is oxidized
B. is called the cathode
C. gains mass at the electrode
D. decreases in oxidation number
2. Which of the following is the strongest oxidizing agent?
A. Cu2+
B. Pb2+
C. Ni2+
D. Sn2+
3. Metallic platinum reacts spontaneously with Au3+(aq) but does not react with
Ag+(aq).
The metals, in order of increasing strength as reducing agents, are
A. Ag, Pt, Au
B. Pt, Au, Ag
C. Au, Ag, Pt
D. Au, Pt, Ag
4. The oxidizing agent in the above reaction is
A. Fe2+
B. Fe3+
C. Mn2+
D. MnO4-
5. MnO4- + 5Fe2+ + 8H+ → Mn2+ + 5Fe3+ + 4H2O
During the reaction, electrons transfer from
A. Fe3+ to Fe2+
B. Fe2+ to MnO4-
C. MnO4- to Fe2+
D. MnO4- to Mn2+
6. As an element is oxidized, its oxidation number
A. increases as electrons are lost
B. decreases as electrons are lost
C. increases as electrons are gained
D. decreases as electrons are gained
7. A solution of 1.0 M Pb(NO3)2 will not react with a container made of
A. Cu
B. Fe
C. Sn
D. Zn
8. A spontaneous redox reaction occurs when a piece of iron is placed in 1.0 M
CuSO4. The reducing agent is
A. Fe
B. Cu2+
C. H2O
D. SO42-
9. A substance is oxidized when it
A. loses protons
B. gains protons
C. loses electrons
D. gains electrons
10. A strip of titanium, Ti, is placed in 1.0 M Sn(NO3)2. The shiny surface of the
titanium darkens, indication that a reaction has
occurred. From this observation it may be concluded that
A. Ti2+ is a weaker reducing agent than Sn2+
B. Ti2+ is a weaker oxidizing agent than Sn2+
C. Ti2+ is a stronger reducing agent than Sn2+
D. Ti2+ is a stronger oxidizing agent than Sn2+
11. Consider the following redox reaction : Hg2+ + Cu → Hg + Cu2+ . In this
reaction, Hg2+ is a
A. weaker reducing agent than Cu2+
B. weaker oxidizing agent than Cu2+
C. stronger reducing agent than Cu2+
D. stronger oxidizing agent than Cu2+
12. The species which gains electrons in a redox reaction
A. loses mass
B. is oxidized
C. is the oxidizing agent
D. increases in oxidization number
13. Samples of Uranium, Vanadium and Yttrium (U, V, Y) were placed in solutions
containing the metallic ions U3+, V2+, and Y3+. The following observations were
recorded.
Trial Ion Metal Observation
1 U3+ Y reaction
2 V2+ U reaction
3 V2+ Y reaction
4 Y3+ V no reaction
The oxidizing agents from the strongest to the weakest are
A. V2+, U3+, Y3+
B. U3+, V2+, Y3+
C. Y3+, U3+, V2+
D. V2+, Y3+, U3+
14. Use the data below to answer the question.
Mo3+(aq) + Ir(s) ® no observable reaction
Ir3+(aq) + Nd(s) ® Nd3+(aq) + Ir(s)
Mo3+(aq) + Nd(s) ® Nd3+(aq) + Mo(s)
From these data it can be predicted that the oxidizing agents, listed from strongest
to weakest, are:
A. Ir3+ Mo3+ Nd3+
3+
B. Mo Nd3+ Ir3+
C. Ir3+ Nd3+ Mo3+
D. Mo Ir Nd
15. Which process could cause X2-(aq) to change to X+(aq)?
A. Z(s) ® Z3-(aq)
B. Z(s) ® Z3+(aq)
C. Z2-(aq) ® Z+(aq)
D. Z3-(aq) ® Z(s)
16. In the reaction, what is the reducing agent?
4 Zn(s) + 10 H+(aq) + NO3-(aq) ® NH4+(aq) + 4 Zn2+(aq) + 3 H2O(l)
A. Zn(s)
B. H+(aq)
C. Zn2+(aq)
D. NO3-(aq)
17. A student observed the reactions between four different metals and the solutions
of their ions, and then recorded these 'spontaneous' reactions.
I. W(s) + X+(aq) ® W+(aq) + X(s)
+
II. X(s) + Y (aq) ® X+(aq) + Y(s)
III. Y(s) + Z+(aq) ® Y+(aq) + Z(s)
IV. X(s) + W+(aq) ® X+(aq) + W(s)
V. X(s) + Z+(aq) ® X+(aq) + Z(s)
If equation I is correct, which equation did the student record incorrectly?
A. II
B. III
C. IV
D. V
18. The reaction below proceeds spontaneously.
A2+(aq) + X(s) ® A(s) + X2+(aq)
Elements A(s) and X(s) respectively, could be
A. Cr2+ and Co
B. Pb2+ and Cu
C. Co2+ and Cu
D. Ni2+ and Zn
19. A piece of Sn(s) was placed in the following solutions:
I. Cu(NO3)2(aq)
II. Hg(NO3)2(aq)
III. AgNO3(aq)
IV. Fe(NO3)2(aq)
A spontaneous reaction will occur in all solutions except
A. I
B. II
C. III
D. IV
20. Theoretically, a reducing agent can be described as a substance that
A. loses electrons and becomes reduced.
B. loses electrons and causes reduction.
C. gains electrons and causes oxidation.
D. gains electrons and becomes reduced.
21. In the reaction
Cu(s) + 2Ag+(aq) ® Cu2+(aq) + 2Ag(s)
A. Cu(s) is reduced by the oxidizing agent.
B. Ag+(aq) is the reducing agent and Cu(s) is reduced.
C. Cu(s) is the reducing agent and Ag+(aq) is reduced.
D. Cu(s) is the oxidizing agent and Ag+(aq) is oxidized.
22. Which of the following reactions is non-spontaneous?
A. I2(s) + Fe(s) ® 2I-(aq) + Fe2+(aq)
B. Ni2+(aq) + Sn2+(aq) ® Ni(s) + Sn4+(aq)
+ -
C. 2Li(s) + 2H2O(l) ® 2Li (aq) + 2 OH (aq) + H2(g)
D. 2Cl2(g) + 2 H2O(l) ® 4Cl-(aq) + O2(g) + 4H+(aq)
23. Which of the following best describes the process of oxidation?
A. the process in which oxygen is produced
B. the process in which electrons are added
C. the process in which the oxidation number decreases
D. the process in which the oxidation number increases
24. What is the oxidation number of N in the mercury (II) compound Hg(NH3)2Cl2
A. -6
B. -4
C. -3
D. +2
25. Which of the following combinations will react spontaneously under standard
conditions?
A. Ag + Br2
B. Ni + Co2+
C. Zn + Mg2+
D. Au + HNO3
26. Identify the substance that is oxidized in the following equation:
Br2 + SO2(g) + K2SO4 + 2H2O ® H2SO4 + 2KBr
A. Br2
B. SO2
C. H2O
D. K2SO4
27 What is the reducing agent in the following equation?
Fe2+ + 2I- ® Fe(s) + I2(s)
A. I2
B. I-
C. Fe2+
D. Fe3+
28. What is the oxidation number of C in the C3H5O2- ion ?
A. -1/3
B. -2/3
C. -1
D. -2
29. Which of the following best describes what happens when lead solid is placed in a
1.0 M solution of Cu(NO3)2?
A. The solution turns a darker blue.
B. No changes are observed.
C. Copper solid forms on the lead and the solution changes colour.
D. The mass of lead solid increases and the solution does not change colour.
30. Identify the reducing agent in the following equation:
Zn + 2MnO2 + H2O ⇌ Zn(OH)2 + 2MnO(OH)
A. Zn
B. H2O
C. MnO2
D. Zn(OH)2
Redox Quiz #4 Electrochemical Cells/Electrolytic Cells Answers
1. In the electrochemical call above, the electrons flow from
A. zinc to lead and the mass of zinc increases
B. zinc to lead and the mass of lead increases
C. lead to zinc and the mass of zinc increases
D. lead to zinc and the mass of lead increases
2. The initial cell voltage is
A. -0.89 V
B. -0.63 V
C. +0.63 V
D. +0.89 V
3. In an operating lead-zinc electrochemical cell shown above, the cathode
A. gains mass as anions are reduced
B. loses mass as anions are reduced
C. gains mass as cations are reduced
D. loses mass as cations are reduced
4. The equation for the half-reaction at the anode is
A. Zn2+ + 2e- → Zn
B. Pb2+ + 2e- → Pb
C. Zn → Zn2+ + 2e-
D. Pb → Pb2+ + 2e-
5. The equation for the half-reaction at the cathode is
A. Zn2+ + 2e- → Zn
B. Pb2+ + 2e- → Pb
C. Zn → Zn2+ + 2e-
D. Pb → Pb2+ + 2e-
6. The direction of electron flow in an electrochemical cell is from
A. anode to cathode through the external wire
B. cathode to anode through the external wire
C. anode to cathode through the external wire and back through the salt bridge
D. cathode to anode through the external wire and back through the salt bridge
7. Which of the following is formed at the anode during the electrolysis of 1.0 M NaI?
A. I2
B. O2
C. H2
D. Na
Molten MgCl2
8. As this cell operates
A. Cl- is oxidized at the anode
B. Mg2+ is oxidized at the anode
C. Cl- is oxidized at the cathode
D. Mg2+ is oxidized at the cathode
9. In an operating electrochemical cell, the anions migrate
A. towards the anode through the wire
B. towards the cathode through the wire
C. towards the anode through the salt bridge
D. towards the cathode through the salt bridge
10. As the above electrochemical cell operates
A. nitrate ions migrate into the copper half-cell
B. copper (II) ions migrate through the salt bridge
C. magnesium ions migrate through the salt bridge
D. potassium ions migrate into the magnesium half-cell
11. In the above electrochemical cell, the reaction at the anode is
A. Cu → Cu2+ + 2e-
B. Cu2+ + 2e- → Cu
C. Mg → Mg2+ + 2e-
D. Mg2+ + 2e- → Mg
12. In the above electrochemical cell, the initial voltage is
A. 2.03 V
B. 2.52 V
C. 2.71 V
D. 2.89 V
13. Which of the following aqueous solutions produces H2(g) and O2(g) during electrolysis
A. 1.0 M KI
B. 1.0 M CuI2
C. 1.0 M K2SO4
D. 1.0 M CuSO4
14. In the electrolysis of molten zinc chloride, the half-reaction at the anode is
A. Cl2 + 2e- → 2Cl-
B. 2Cl- → Cl2 + 2e-
C. Zn2+ 2e- → Zn
D. Zn → Zn2+ + 2e-
15. The initial cell voltage at 25oC is
A. -1.06 V
B. -0.54 V
C. +0.54 V
D. +1.06 V
16. The balanced equation for the overall reaction is
A. Ni+(aq) + Ag(s) → Ag+(aq) + Ni(s)
B. Ni(s) + Ag+(aq) → Ag(s) + Ni+(aq)
C. Ni2+(aq) + 2Ag(s) → 2Ag+(aq) + Ni(s)
D. Ni(s) + 2Ag+(aq) → 2Ag(s) + Ni2+(aq)
17. This redox reaction occurs because
A. Ag(s) is a stronger oxidizing agent than Ni(s)
B. Ag(s) is a weaker reducing agent than Ni(s)
C. Ag+(aq) is a stronger reducing agent than Ni2+(aq)
D. Ag+(aq) is a weaker oxidizing agent than Ni2+(aq)
18. The direction of the electron flow is
A. from Au to Pb through the wire
B. from Pb to Au from the wire
C. from Au to Pb through the salt bridge
D. from Pb to Au through the salt bridge
19. As the cell operates
A. NO3- and K+ will migrate toward the Pb half-cell
B. NO3- and K+ will migrate toward the Au half-cell
C. NO3- will migrate toward the Pb half-cell and K+ will migrate toward the Au half-
cell
D. NO3- will migrate toward the Au half-cell and K+ will migrate toward the Pb half-
cell
20. The initial voltage is
A. -1.37 V
B. 0.00 V
C. 1.37 V
D. 1.63 V
21. Which of the following is a balanced half-reaction in base?
A. Cl2 + 3H2O → ClO3- + 6H+ + 5e-
B. Cl2 + 6OH- → ClO3- + 5e- + 3H2O
C. Cl2 + 6H2O → 2ClO3- + 12H+ + 10e-
D. Cl2 + 12OH- → 2ClO3- + 6H2O + 10e-
22. In which of the following unbalanced equations does chromium undergo oxidation?
A. Cr3+ → Cr
B. Cr3+ → Cr2+
C. Cr3+ → Cr2O72-
D. CrO42- → Cr2O72-
23. Which of the following is formed at the anode and cathode during the electrolysis of
1.0 M Na2SO4?
Anode Cathode
A. O2 H2
B. H2 O2
C. H2 Na
D. S Na
24. Consider the electrolytic cell shown in the following diagram:
Which of the following describes the anion movement and electrode masses for the above
cell?
Anion Movement Mass of Pt Electrode Mass of Cu Electrode
A. to the Cu increases increases
B. to the Cu increases decreases
C. to the Pt decreases increases
D. to the Pt decreases decreases
25. Which of the following describes electrolysis?
A. a process that uses electrical energy to cause a spontaneous reaction
B. a process that generates electrical energy using a spontaneous reaction
C. a process that uses electrical energy to cause a non-spontaneous reaction
D. a process that generates electrical energy using a non-spontaneous reaction
26. What products would form at the anode and cathode as this cell operates?
Anode Cathode
A. I2 Ni
B. Ni I2
C. O2 H2
D. Cu2+ Ni
27. In the above cell, if 1.0 M NiI2 is replaced with molten NiI2, what products would form at
the electrodes?
Anode Cathode
A. I2 Ni
B. Ni I2
C. O2 H2
D. Cu2+ Ni
28. In the above cell, which describes the movement of the electrons?
A. They move from left to right towards the anode.
B. They move from right to left towards the anode.
C. They move from right to left towards the cathode.
D. They move from left to right towards the cathode.
29. Which of the following best describes what happens to the mass of the anode and the
mass of the cathode as the cell operates?
Anode Mass Cathode Mass
A. decreases increases
B. decreases no change
C. no change decreases
D. no change no change
30. What is the standard voltage E0 for the cell?
A. 0.43 V
B. 0.77 V
C. 1.34 V
D. 1.68 V
Equilibrium Quiz # 1 Approaching Equilibrium Answers
1. Consider the following equilibrium: H2O(g) + CO(g) ⇄ H2(g) + CO2(g)
A closed container is initially filled with H2O and CO. As the reaction proceeds towards
equilibrium the
A. [CO] and [CO2] both increase
B. [ CO] and [CO2] both decrease
C. [CO] increases and [CO2] decreases
D. [CO] decreases and [CO2] increases
2. Consider the following equilibrium: 2SO3(g) ⇄ 2SO2(g) + O2(g)
At equilibrium, the rate of decomposition of SO3
A. Equals the rate of formation of O2
B. Equals the rate of formation of SO3
C. Is less than the rate of formation of O2
D. Is less than the rate of formation of SO3
3. Which of the following is true for all equilibrium systems?
A. The mass of reactants is equal to the mass of products
B. Addition of a catalyst changes the equilibrium concentrations
C. The concentration of reactants is equal to the concentration of products
D. The rate of the forward reaction is equal to the rate of the reverse reaction
4. Consider the following: 2NH3(g) ⇄ N2(g) + 3H2(g)
A flask is initially filled with NH3. As the system approaches equilibrium, the rate of the
forward reaction
A. Increases as the rate of the reverse reaction decreases
B. Decreases as the rate of the reverse reaction increases
C. Increases as the rate of the reverse reaction increases
D. Decreases as the rate of the reverse reaction decreases
5. A system at equilibrium is said to be dynamic because at equilibrium the
A. Temperature does not change
B. Macroscopic properties are constant
C. Forward and reverse reactions continue to occur
D. Concentrations of reactants and products are constant
6. In all systems at equilibrium, the
A. Concentration of reactants is less than the concentration of products
B. Concentration of reactants and the concentration of products are equal
C. Concentration of reactants is greater than the concentration of products
D. Concentration of reactants and the concentration of products are constant
7. Consider the following equilibrium: H2O(g) + CO(g) ⇄ H2(g) + CO2(g)
At high temperature, H2O and CO are placed in a closed container. As the system
approaches equilibrium, the
A. Rate of the forward and reverse reaction both increase
B. Rate of the forward and reverse reaction both decrease
C. Rate of the forward reaction decreases and the rate of the reverse reaction
increases
D. Rate of the forward reaction increases and the rate of the reverse reaction decreases
8. Which of the following statements are true for all equilibrium systems?
I. Macroscopic Properties are constant
II. Mass of the reactants equals mass of the products
III Equilibrium can be achieved from either products or reactants
A. I and II only
B. I and III only
C. II and III only
D. I, II, and III
9. Consider the following equilibrium: N2O4(g) + heat ⇄ 2NO2(g)
Initially, a 1.0 L container is filled with 2.0 mol of NO2. As the system approaches
equilibrium, the rate of reaction of NO2
A. Increases and [ N2O4 ] increases
B. Increases and [ N2O4 ] decreases
C. Decreases and [ N2O4 ] increases
D. Decreases and [ N2O4 ] decreases
10. Consider the following equilibrium: N2(g) + O2(g) ⇄ 2NO(g)
Nitrogen gas and oxygen react when placed in a closed container. As the reaction
proceeds towards equilibrium,
the rate of the reverse reaction
A. Increases as the concentration of products decreases
B. Decreases as the concentration of products decreases
C. Increases as the concentration of products increases
D. Decreases as the concentration of products increases
11. Consider the following
I Constant Temperature
II Equal concentrations of reactants and
products
III Equal rates of forward and reverse reactions
A system at equilibrium must have
A. I and II only
B. I and III only
C. II and III only
D. I, II , and III
12. Consider the following: N2O4(g) ⇌ 2NO2(g)
Colourless Brown
NO2 is placed in a flask at a constant temperature. Which of the following is true as the
system approaches equilibrium?
A. The colour gets darker as [NO2] increases.
B. The colour gets lighter as [NO2] decreases.
C. The colour gets darker as [N2O4] increases.
D. The colour gets lighter as [N2O4] decreases.
13. Consider the following: N2O4(g) ⇌ 2NO2(g)
Colourless Brown
N2O4 is placed in a flask at a constant temperature. Which of the following is true as the
system approaches equilibrium?
A. The colour gets darker as [NO2] increases.
B. The colour gets lighter as [NO2] decreases.
C. The colour gets darker as [N2O4] increases.
D. The colour gets lighter as [N2O4] decreases.
14. Consider the following equilibrium: PCl3(g) + Cl2(g) ⇌ PCl5(g)
If PCl5 is put in a container, how will the reaction rates change as the system approaches
equilibrium?
Forward Rate Reverse Rate
A. increases increases
B. increases decreases
C. decreases decreases
D. decreases increases
15. Consider the following equilibrium system: H2O(g) + CO(g) ⇌ CO2(g) + H2(g)
2.00 mole of CO2 and 2.00 mole of H2 are placed in a container and the system
approached equilibrium.
The following changes occur:
[CO2] [H2] [CO]
A. increases decreases decreases
B. increases increases decreases
C. decreases increases increases
D. decreases decreases increases
16. For the equilibrium system below:
Zn(s) + CuSO4(aq) ® Cu(s) + ZnSO4(aq)
We would know the system is at equilibrium because:
A. [Cu2+] = [Zn2+]
B. Cu(s) = Zn(s)
C. the mass of Cu(s) remains constant.
D. the mass of the entire system remains constant.
17. Which of the factors below is not a condition necessary for equilibrium?
A. a closed system
B. a constant temperature
C. equal forward and reverse reaction rates
D. equal concentrations of reactants and products
18. Products are placed in a beaker. How do the rates of the forward and reverse reactions
changes
the system proceeds to equilibrium?
Forward Rate Reverse Rate
A. increases increases
B. increases decreases
C. decreases increases
D. decreases decreases
19. Which of the factors below is not a condition necessary for equilibrium?
A. constant macroscopic properties
B. constant concentrations of reactant and product
C. equal forward and reverse reaction rates
D. a high activation energy
Equilibrium Quiz #2 LeChatelier’s Principle Answers
1. Consider the following reaction: 2SO2(g) + O2(g) ⇄ 2SO3(g) ∆H = -197 kJ/mol
Which of the following will not shift the equilibrium to the right?
A. Adding more O2
B. Adding a catalyst
C. Increasing the pressure
D. Lowing the temperature
2. Consider the following equilibrium system: CaCO3(s) ⇄ CaO(s) + CO2(g)
Which one of the following changes would cause the above system to shift left?
A. Add more CaO
B. Remove CaCO3
C. Decrease volume
D. Increase surface area of CaO
3. Consider the following equilibrium: SO2Cl2(g) + energy ⇄ SO2(g) + Cl2(g)
When the temperature is decreased, the equilibrium shifts
A. Left and [ SO2Cl2 ] increases
B. Left and [ SO2Cl2 ] decreases
C. Right and [ SO2Cl2 ] increases
D. Right and [ SO2Cl2 ] increases
4. Consider the following equilibrium: 2SO3(g) ⇄ 2SO2(g) + O2(g)
The volume of the system is decreased at a constant temperature. A new state of
equilibrium is established
by a shift of the original equilibrium to the
A. Left and [SO3] increases
B. Right and [SO3] decreases
C. Left and [SO3] remains unchanged
D. Right and [SO3] remains unchanged
5. Consider the following equilibrium system: CO2(g) + H2(g) ⇄ CO(g) + H2O(g)
Which of the following, when added to the system above, would result in a net decrease
in [H2O]?
A. CO2
B. H2
C. CO
D. H2
6. Consider the following equilibrium: C(s) + 2H2(g) ⇄ CH4(g) + 74 kJ
When a small amount of solid C is added to the system
A. [H2] decreases
B. [CH4] increases
C. The temperature increases
D. All concentrations remain constant
7. Consider the following equilibrium: 2NO(g) + Cl2(g) ⇄ 2NOCl(g)
At constant temperature and volume, Cl2 is added to the above equilibrium system.
As equilibrium re-establishes, the
A. [NOCl] will decrease
B. The temperature increases
C. [NO] will increase
D. [NOCl] will increase
8. Consider the following equilibrium: Cl2O7(g) +8H2(g) ⇄ 2HCl(g) + 7H2O(g)
Which of the following would increase the number of moles of HCl?
A. Increase [H2O]
B. Increase [Cl2O7]
C. Increase total pressure
D. Increase volume of the system
9. Consider the following equilibrium: 2HI(g) ⇄ H2(g) I
+ 2(g) ∆H = -68kJ
Which of the following would cause the equilibrium to shift right?
A. Increasing the volume
B. Decreasing the volume
C. Increasing the temperature
D. Decreasing the temperature
10. A 1.00 L flask contains a gaseous equilibrium system. The addition of reactants to this
flask results in a
A. Shift to the left and decrease in the concentration of products
B. Shift to the left and increase in the concentration of products
C. Shift to the right and decrease in the concentration of products
D. Shift to the right and increase in the concentration of products
11. When the temperature of an equilibrium system is increased, the equilibrium always
shifts to favor the
A. Exothermic reaction
B. Endothermic reaction
C. Formation of products
D. Formation of reactants
12. An equilibrium system shifts left when the
A. Rate of the forward reaction is equal to the rate of the reverse reaction
B. Rate of the forward reaction is less than the rate of the reverse reaction
C. Rate of the forward reaction is greater than the rate of the reverse reaction
A. Rate of the forward reaction and the rate of the reverse reaction are constant
13. Consider the following equilibrium: 2SO2(g) + O2(g) ⇄ 2SO3(g) ∆H = -198 kJ
There will be no shift in the equilibrium when
A. More O2 is added
B. Catalyst is added
C. The volume is increased
D. The temperature is increased
14. Consider the following equilibrium: 2NOCl(g) ⇄ 2NO(g) + Cl2(g)
In a 1.0 L container at equilibrium there are 1.0 mol NOCl, 0.70 mol NO and 0.40 mol
Cl2.
At constant temperature and volume, 0.10 mol NOCl is added. The concentrations in the
“new” equilibrium in comparison to the concentrations in the “old” equilibrium are
A.
B.
C.
D.
[NOCl] [NO] [Cl2]
new = old new = old new = old
new > old new > old new > old
new < old new < old new > old
new < old new > old new > old
15. Consider the following equilibrium: N2O4(g) + 58 kJ ⇄ 2NO2(g)
The equilibrium shifts right when
A. NO2 is added
B. N2O4 is removed
C. The temperature is decreased
D. The volume of the system is increased
16. Consider the following equilibrium: 2SO2(g) + O2(g) ⇄ 2SO 3(g)
Which of the following will shift the equilibrium to the right?
I. Adding more O2
II. Adding more SO3
III. Adding a catalyst
A. I only
B. III only
C. I and II only
D. II and III only
17. Consider the following equilibrium:
energy + 2NaClO3(s) ⇌ 2NaCl(s) + 3O2(g)
Which of the following will cause a shift to the left?
A. adding more O2
B. adding more NaCl
C. removing some NaClO3
D. increasing the temperature
18. Consider the following equilibrium:
CO(g) + 2H2(g) ⇌ CH3OH(g) + energy
Which of the factors below would decrease the concentration of CH3OH at equilibrium?
A. an addition of CO
B. an increase in H2
C. a decrease in the temperature
D. an increase in the temperature
19. Consider the following equilibrium:
energy + 2NaClO3(s) ⇌ 2NaCl(s) + 3O2(g)
Which of the following will cause a shift to the right?
A. adding more O2
B. adding more NaCl
C. removing some NaCl(s)
D. increasing the temperature
20. Consider the following equilibrium: 2SO2(g) + O2(g) ⇄ 2SO 3(g)
Which of the following will shift the equilibrium to the left?
I. Removing O2
II. Adding more SO3
III. Adding a catalyst
A. I only
B. III only
C. I and II only
D. II and III only
21. Consider the following equilibrium: N2O4(g) + energy ⇌ 2NO2(g)
How are N2O4 and NO2 affected by the addition of He into the container at constant
volume.
N2O4 NO2
A. no change no change
B. no change increases
C. increases decreases
D. decreases increases
22. Which of the following stresses will cause a shift to the reactants?
H2(g) + Br2(g) ⇌ 2HBr(g) + energy
A. increase [Br2]
B. increase [H2]
C. decrease temperature
D. increase temperature
23. Which of the following stresses will cause a shift to the products?
H2(g) + Br2(g) ⇌ 2HBr(g) + energy
A. decrease [Br2]
B. decrease [H2]
C. decrease temperature
D. increase temperature
24. Which of the following two stresses will each cause the system to shift to the left?
2SO2(g) + O2(g) ⇄ 2SO 3(g) + energy
A. decrease temperature and decrease [O2]
B. increase temperature and increase [SO3]
C. increase temperature and decrease [SO3]
D. decrease temperature and increase [SO2]
25. SrCO3(s) + 215 kJ ⇌ SrO(s) + CO2(g)
Which of the following conditions would produce the greatest yield of SrO(s)?
Temperature Pressure
A. low low
B. low high
C. high low
D. high high
26. The Haber Process is used to produce ammonia commercially according to the following
equilibrium:
N2(g) + 3H2(g) ⇌ 2NH3(g) + energy
Which of the following conditions will produce the highest yield of ammonia?
A. increase temperature and increase pressure
B. increase temperature and decrease pressure
C. decrease temperature and increase pressure
D. decrease temperature and decrease pressure
27. Consider the following reaction: 2SO2(g) + O2(g) ⇄ 2SO3(g) ∆H = -197 kJ/mol
If the volume is increased what happens to position of the equilibrium?
A. shifts to the right
B. shifts to the left
C. no shift
D. shifts in the exothermic direction
28. Consider the following reaction: 2NH3(g) + energy ⇄ N2(g) + 3H2(g)
If the volume is increased what happens to position of the equilibrium?
A. shifts to the right
B. shifts to the left
C. no shift
D. shifts in the exothermic direction
29. Consider the following reaction: SrCO3(s) + 215 kJ ⇌ SrO(s) + CO2(g)
If the volume is decreased what happens to position of the equilibrium?
A. shifts to the right
B. shifts to the left
C. no shift
D. shifts in the exothermic direction
30. Consider the following reaction: H2(g) + Br2(g) ⇌ 2HBr(g) + energy
If the volume is increased what happens to position of the equilibrium?
A. shifts to the right
B. shifts to the left
C. no shift
D. shifts in the exothermic direction
31. Consider the following reaction: N2O4(g) + energy ⇌ 2NO2(g)
If the volume is decreased what happens to position of the equilibrium?
A. shifts to the right
B. shifts to the left
C. no shift
D. shifts in the exothermic direction
Quiz # 3 Yield/Graphing/LeChatelier’s Principle Answers
1. When a catalyst is added to an equilibrium system, the forward reaction
A. Increases and the reverse decreases
B. Decreases and the reverse decreases
C. Decreases and the reverse increases
D. Increases and the reverse increases
2. Consider the following concentration versus time graph for the equilibrium
N2O4(g) ⇄ 2NO2(g)
“t” TIME(S)
At time= “t”, which one of the following stresses occurred
A. Catalyst was added
B. Pressure was changed
C. Temperature was changed
D. Concentration of NO2 was changed
3. Which of the following reactions will shift left when pressure is increased and when
temperature is decreased?
A. N2(g) + 2O2(g) + heat ⇄ 2NO2(g)
B. N2(g) + 3H2(g) ⇄ 2NH3(g) + heat
C. CH4(g) + H2O(g) + heat ⇄ CO(g) + 3H2(g)
D. CS2(g) + 4H2(g) ⇄ CH4(g) + 2H2S(g) + heat
4. Consider the following graph, which relates to this equilibrium
N2(g) + 3H2(g) ⇄ 2NH3(g) ∆H = -92kJ
Which of the following caused the changes in the concentrations at time t ?
A. Addition of N2
B. Removal of H2
C. Decrease in temperature
D. Decrease in reaction volume
5. Consider the following equilibrium: CH4(g) + H2O(g) + heat ⇄ CO(g) + 3H2(g)
In which of the following will both stresses shift the equilibrium right
A. A decrease in temperature and a decrease in volume
B. An increase in temperature and a decrease in volume
C. A decrease in temperature and an increase in volume
D. An increase in temperature and an increase in volume
6. Consider the following equilibrium system: N2(g) + 3H2(g) ⇄ 2NH3(g) + 92 kJ
In order to maximize the yield for this reaction, the best conditions are:
A. Low pressure and low temperature
B. Low pressure and high temperature
C. High temperature and low pressure
D. High pressure and low temperature
7. Consider the following equilibrium system: NH3(aq) + H2O(l) ⇄ NH+4(aq) + OH--(aq)
Which of the following when added to the above equilibrium system would cause an
increase in [ OH-]
A. NH3
B. H2O
C. NH4+
D. HCl
8. Consider the following reversible reaction: Fe3+(aq) + SCN-(aq) ⇄ FeSCN2+(aq)
A solution of Fe(NO3)3 is added to a solution of KSCN. Which one of the following
statements
describes the changes in forward and reverse reaction rates as the reaction moves towards
equilibrium?
A. Forward and reverse rates increase
B. Forward and reverse rates decrease
C. Forward rate increases and reverse rate decrease
D. Forward rate decreases and reverse rate increase
9. Consider the following equilibrium: N2(g) + O2(g) ⇄ 2NO(g) ∆H= + 181 kJ
When the temperature is decreased, the equilibrium
A. Shifts left and [NO] decreases
B. Shifts left and [NO] increases
C. Shifts right and [NO] increases
D. Shifts right and [NO] decreases
10. Consider the following equilibrium: N2(g) + 3H2(g) ⇄ 2NH3(g) + 92 kJ
In which of the following will both changes shift the equilibrium right?
A. An increase in volume and a decrease in temperature
B. An increase in volume and a increase in temperature
C. A decrease in volume and a decrease in temperature
D. A decrease in volume and an increase in temperature
11. Consider the following equilibrium: CaCO3(s) + 556 kJ ⇄ CaCO(s) + CO2(g)
The equilibrium will shift to the right
A. CO2 is added
B. CaCO3(s) is added
C. The temperature is increased
D. The temperature is decreased
12. Consider the following equilibrium: SO2(g) + NO2(g) ⇄ SO3(g) + NO(g) + energy
The equilibrium does not shift with a change in the
A. Volume
B. Temperature
C. Concentration of products
D. Concentration of reactants
13. Consider the following equilibrium: 2Hl(g) ⇄ H2(g) + I2(g)
At constant temperature and volume, more I2 is added to the above equilibrium.
A new state of equilibrium results from a shift to the
A. Left with a net decrease in [H2]
B. Left with a net increase in [H2]
C. Right with a net increase in [H2]
D. Right with a net decrease in [H2]
14. Consider the following diagram for the equilibrium system:
Energy + N2O4(g) ⇄ 2NO2(g)
A. [NO2] was increased.
B. [N2O4] was decreased.
C. Temperature was increased.
D. Temperature was decreased.
15. Consider the following diagram for the equilibrium system:
Energy + N2O4(g) ⇄ 2NO2(g)
A. [NO2] was increased.
B. [N2O4] was decreased.
C. Temperature was increased.
D. Temperature was decreased.
16. Consider the following diagram for the equilibrium system:
Energy + N2O4(g) ⇄ 2NO2(g)
A. [NO2] was increased.
B. [N2O4] was decreased.
C. Temperature was increased.
D. The Volume was decreased.
17. Which of the following describes the temperature and pressure needed for
the maximum yield of NO2?
Energy + N2O4(g) ⇄ 2NO2(g)
Temperature Pressure
A. low low
B. low high
C. high low
D. high high
18. Which of the following describes the temperature and pressure needed for
the maximum yield of NH3?
N2(g) + 3H2(g) ⇄ 2NH3(g) + 92 kJ
Temperature Pressure
A. low low
B. low high
C. high low
D. high high
19. Which of the following describes the temperature and pressure needed for
the maximum yield of CO2?
CaCO3(s) ⇄ CaCO(s) + CO2(g) ΔH = +215 kJ
Temperature Pressure
A. low low
B. low high
C. high low
D. high high
20. Consider the following equilibrium: CaCO3(s) ⇌ CaO(s) + CO2(g) ΔH = +160 kJ
Which starting materials could establish an equilibrium?
1 CaCO3(s) 2 CaO(s)
3 CaO(s) and CO2(g) 4 CaCO3(s) and CO2(g)
A. 1, 2, 3 only
B. 1, 2, 4 only
C. 1, 3, 4 only
D. 3, 4 only
Consider the following reaction for the next five questions 21 to 25.
4NH3(g) + 3O2(g) ⇌ 2N2(g) + 6H2O(l) + 1250 kJ
21. Which of the following would cause the concentration of NH3 at equilibrium to increase?
A. an increase in [O2]
B. a increase in volume
C. a decrease in temperature
D. an increase in temperature
22. What happens when NH3 is added to the above system?
Equilibrium [N2]
A. no shift unchanged
B. shifts right decreases
C. shifts right increases
D. shifts left increases
23. If some O2 is removed from the system, what happens to the forward and
reverse reaction rates after equilibrium is re-established?
Forward Reaction Rate Reverse Reaction Rate
A. increases decreases
B. decreases decreases
C. increases increases
D. decreases increases
24. If some O2 is injected into the system, what happens to the forward and
reverse reaction rates during the shift to re-establish equilibrium?
Forward Reaction Rate Reverse Reaction Rate
A. increases decreases
B. decreases decreases
C. increases increases
D. decreases increases
25. Consider the equilibrium: N2(g) + 3H2(g) ⇄ 2NH3(g) + 92 kJ
The following diagram represents the rate of the reverse reaction.
t1
Which of the following stresses explains what happened at t1 ?
A. [H2] increased.
B. [N2] decreased.
C. [NH3] increased.
D. [NH3] decreased.
26. Consider the equilibrium: N2(g) + 3H2(g) ⇄ 2NH3(g) + 92 kJ
The following diagram represents the rate of the forward reaction.
t1
Which of the following stresses explains what happened at t1 ?
A. [H2] increased.
B. temperature was lowered
C. [NH3] increased.
D. [NH3] decreased.
27. Consider the equilibrium: N2(g) + 3H2(g) ⇄ 2NH3(g) + 92 kJ
The following diagram represents the rate of the reverse reaction.
t1
Which of the following stresses explains what happened at t1 ?
A. [H2] increased.
B. [N2] decreased.
C. [NH3] increased.
D. [NH3] decreased.
28. A small amount of NaOH is added to the following equilibrium system:
2CrO42- + 2H+ ⇌ Cr2O72-(aq) + H2O(l)
How do the [CrO42-] and the reverse reaction rate change as equilibrium is re-established?
[CrO42-] Reverse Rate
A. increases increases
B. increases decreases
C. decreases decreases
D. decreases increases
29. A small amount of H2SO4 is added to the following equilibrium system:
2CrO42- + 2H+ ⇌ Cr2O72-(aq) + H2O(l)
How do the [CrO42-] and the reverse reaction rate change as equilibrium is re-established?
[CrO42-] Reverse Rate
A. increases increases
B. increases decreases
C. decreases decreases
D. decreases increases
30. A small amount of NaOH is added to the following equilibrium system:
2CrO42- + 2H+ ⇌ Cr2O72-(aq) + H2O(l)
How do the [Cr2O72-] and the reverse reaction rate change as equilibrium is re-
established?
[Cr2O72-] Reverse Rate
A. increases increases
B. increases decreases
C. decreases decreases
D. decreases increases
31. A small amount of H2SO4 is added to the following equilibrium system:
2CrO42- + 2H+ ⇌ Cr2O72-(aq) + H2O(l)
How do the [Cr2O72-] and the reverse reaction rate change as equilibrium is re-
established?
[Cr2O72-] Reverse Rate
A. increases increases
B. increases decreases
C. decreases decreases
D. decreases increases
Quiz #4 Writing and Calculating Keq Answers
1. The equilibrium constant expression for the following reaction is:
2Hg(l) + O2(g) ⇄ 2HgO(s)
A. Keq = 1/[O2]
B. Keq = [O2]
C. Keq = [2HgO] / [O2] [2Hg]
D. Keq = [HgO]2 / [Hg]2[O2]
2. Identify the equilibrium system that least favors the formation of products
A. 2HgO ⇄ 2Hg + O2 Keq = 1.2 x 10-22
B. CH3COOH + H2O ⇄ H3O+ + CH3COO- Keq = 1.8 x 10-5
C. 2NO + O2 ⇄ 2NO2 Keq = 6.5 x 105
D. H2 + Cl2 ⇄ 2HCl Keq = 1.8 x 1033
3. Consider the following equilibrium system: 3O2(g) ⇄ 2O3(g) Keq = 1
Which equation compares the concentration of oxygen and ozone?
A. [O2] = [O3]2/3
B. [O2] = [O3]
C. [O2] = [O3]3/2
D. [O2] 2/5 = [O3]
4. For which of the following equilibrium does Keq = [O2]
A. O2(l) ⇄ O2(g)
B. 2O3(g) ⇄ 3O2(g)
C. 2H2O(l) ⇄ 2H2(g) + O2(g)
D. 2Hg(s) + O2(g) ⇄ 2HgO(s)
5. Consider the following equilibrium system at 25O C : 2SO2(g) + O2(g) ⇄ 2SO3(g)
At equilibrium, [SO2] is 4.00 x 10-3 mol/L, [O2] = 4.00 x 10-3 mol/L and
[SO3] is 2.33 x 10-3 mol/L. From this data, the Keq value for the above system is
A. 6.85 x 10-3
B. 1.18 x 10-2
C. 84.8
D. 146
6. Consider the following equilibrium system: PCl5(g) ⇄ PCl3(g) + Cl2(g)
At equilibrium, [PCl5] is a 0.400 M. [PCl3] is 1.50 M and [Cl2] is 0.600 M.
The Keq for the reaction is
A. 0.360
B. 0.444
C. 0.900
D. 2.25
7. Consider the following equilibrium: 2H2S(g) ⇄ 2H2(g) + S2(g)
At equilibrium, [H2S] = 0.50 mol/L. [H2] = 0.10 mol/L and [S2] = 0.40 mol/L.
The value of Keq is calculated using the ratio
A (0.10)(0.40)
(0.50)
B. (0.10)2(0.40)
(0.50)2
C. (0.50)
(0.10)(0.50)
D. (0.50)2
(0.10)2(0.40)
8. Consider the following equilibrium: 2NO(g) + Cl2(g) ⇄ 2NOCl(g) Keq = 12
At equilibrium, [NOCl] = 1.60 mol/L and [NO] = 0.80 mol/L. The [Cl2] is
A. 0.17 mol/L
B. 0.27 mol/L
C. 0.33 mol/L
D. 3.0 mol/L
9. Consider the following equilibrium: I2(s) + H2O(l) ⇄ H+(aq) + I-(aq) + HOI(aq)
The equilibrium constant expression for the above system is
A. Keq = [H+][I-]
B. Keq = [H+][I-][HOI]
C. Keq = [H+][I-][HOI]
[I2][H2O]
D. Keq = [H+][I-][HOI]
[H2O]
10. Consider the following equilibrium: 2CO(g) + O2(g) ⇄ 2CO2(g)
The ratio used to calculate the equilibrium constant is
A. [2CO]2[O2]
[2CO2]2
B. [2CO2]2
[2CO]2[O2]
C. [CO]2[O2]
[CO2]2
D. [CO2]2
[CO]2[O2]
11. Consider the following equilibrium: 2Fe(s) + 3H2O(g) ⇄ Fe2O3(s) + 3H2(g)
The equilibrium constant expression is
A. Keq = [Fe2O3][H2]3
[Fe]2[H2O]3
B. Keq = [Fe2O3][3H2]
[2Fe] [3H2O]
C. Keq = [H2]3
[H2O]3
D. Keq = [H2]3
12. Consider the following equilibrium: N2O4(g) ⇄ 2NO2(g) Keq = 0.133
At equilibrium, the [N2O4] is equal to
A. 0.133
[NO2]
B. [NO2]
0.133
C. 0.133
[NO2]2
D. [NO2]2
0.133
13. Consider the following equilibrium: 4KO2(s) + 2H2O(g) ⇄ 4KOH(s) + 3O2(g)
The equilibrium constant expression is
A. Keq = [KOH]4[O2]3
[KO2]4[H2O]2
B. Keq = [O2]3
[H2O]2
C. Keq = [KO2]4[H2O]2
[KOH]4[O2]3
D. Keq = [H2O]2
[O2]3
14. Consider the following equilibrium: C(s) + H2O(g) ⇄ CO(g) + H2(g)
The contents of a 1.00 L container at equilibrium were analyzed and found to
contain 0.20 mol C, 0.20 mol H2O, 0.60 mol CO and 0.60 mol H2. The equilibrium
constant is
A. 0.11
B. 0.56
C. 1.8
D. 9.0
15. Consider the following equilibrium: N2O4(g) ⇄ 2NO2(g) Keq = 4.61 x 10-3
A 1.00 L container at equilibrium was analyzed and found to contain 0.0200 moles NO2.
At equilibrium, the concentration of N2O4 is
A. 0.0868 mol/L
B. 0.230 mol/L
C. 4.34 mol/L
D. 11.5 mol/L
16. Consider the following equilibrium: CH4(g) + H2O(g) ⇄ CO(g) + 3H2(g) Keq= 5.7
At equilibrium, the [CH4] = 0.40 mol/L [CO] = 0.30 mol/L and [H2] = 0.80 mol/L.
The [H2O] is
A. 0.067 mol/L
B. 0.11 mol/L
C. 2.2 mol/L
D. 5.3 mol/L
17. Consider the following equilibrium: H2(g) + I2(g) ⇄ 2HI(g)
At equilibrium, the [H2] = 0.020 mol/L. [I2] = 0.020 mol/L and [HI] = 0.160 mol/L.
The value of the equilibrium constant is
A. 2.5 x 10-3
B. 1.6 x 10-2
C. 6.4 x 101
D. 4.0 x 102
18. Consider the following constant expression: Keq = [CO2]. Which one of the following
equilibrium systems does the above expression represent?
A. CO2(g) ⇄ CO2(s)
B. PbO(s) + CO2(g) ⇄ PbCO3(s)
C. CaCO3(s) ⇄ CaO(s) + CO2(g)
D. H2CO3(aq) ⇄ H2O(l) + CO2(aq)
19. Given the following equilibrium system: Br2(g) ⇄ Br2(l)
The equilibrium constant expression for the above system is
A. Keq = [Br2(l)]
[Br2(g)]
B. Keq = [Br2(g)]
C. Keq = 1 __
[Br2(g)]
D. Keq = [Br2(g)] [Br2(g)]
20. Consider the following equilibrium: CO(g) + 2H2(g) ⇄ CH3OH(g) + 91 kJ
A change in temperature of the above system increases the value of the equilibrium
constant.
The new state of equilibrium was established by a shift
A. Left as a result of a decrease in temperature
B. Right as a result of a decrease in temperature
C. Left as a result of an increase in temperature
D. Right as a result of an increase in temperature
21. Consider the equilibrium: SrCO3(s) ⇌ SrO(s) + CO2(g) In a 2.5 L container
at equilibrium there are 2.42 g CO2, 1.00 g SrCO3 and 1.00 SrO.
Which of the following is the value of Keq?
A. 0.022
B. 0.011
C. 0.020
D. 91
22. Consider the following equilibrium: CCl4(g) ⇌ C(s) + 2Cl2(g)
Initially, 0.62 mol CCl4 was placed in a 2.0L container. At equilibrium, [Cl2] = 0.060
M.
Which of the following is the value of Keq?
A. 0.00039
B. 0.013
C. 0.014
D. 0.78
23. Consider the following equilibrium: CH4(g) + H2O(g) ⇌ CO(g) + 3H2(g)
At equilibrium, 1.20 mol CH4, 1.20 mol H2O, 0.080 mol CO and 0.040 mol H2
are present in a 2.0 L container. What is the value of Keq ?
A. 4.3 x 10-6
B. 2.2 x 10-2
C. 2.2 x 10-4
D. 8.9 x 10-7
24. Consider the following equilibrium: Cr2O72-(aq) + 2OH-(aq) ⇌ 2CrO42-(aq) + H2O(l)
The concentration of ions at equilibrium was measured at a specific temperature and
found to be
[CrO42-] = 0.100 M, [Cr2O72-] = 0.20 M, and [OH-] = 0.11 M. What is the Keq?
A. 41
B. 4.13
C. 0.83
D. 0.11
25. Consider the following equilibrium: Cr2O72-(aq) + 2OH-(aq) ⇌ 2CrO42-(aq) + H2O(l)
Keq = 4.14
The concentration of ions at equilibrium was measured at a specific temperature and
found to be
[Cr2O72-] = 0.100 M and [OH-] = 0.20 M. What is the equilibrium [CrO42-] ?
A. 0.017 M
B. 0.083 M
C. 0.13 M
D. 0.32 M
26. Consider the following equilibrium: 2COF2(g) ⇌ CO2(g) + CF4(g) Initially, 0.32 M CO2
and 0.40 M CF4
are placed in a container. At equilibrium, it is found that the [COF2] is 0.16 M. What is
the value of Keq?
A. 0.026
B. 1.5
C. 9.3
D. 3.0
27. Consider the following equilibrium: Cr2O72-(aq) + 2OH-(aq) ⇌ 2CrO42-(aq) + H2O(l)
Keq = 4.14
The concentration of ions at equilibrium was measured at a specific temperature and
found to be
[CrO42-] = 0.100 M and [OH-] = 0.20 M. What is the equilibrium [Cr2O72-] ?
A. 0.060 M
B. 0.083 M
C. 0.13 M
D. 0.32 M
28. Consider the following equilibrium: Cr2O72-(aq) + 2OH-(aq) ⇌ 2CrO42-(aq) + H2O(l)
Keq = 4.14
The concentration of ions at equilibrium was measured at a specific temperature and
found to be
[CrO42-] = 0.100 M and [Cr2O72-] = 0.20 M. What is the equilibrium [OH-]?
A. 0.012 M
B. 0.083 M
C. 0.13 M
D. 0.11 M
29. Consider the following equilibrium: 2COF2(g) ⇌ CO2(g) + CF4(g) Initially, 0.16 M CO2
and 0.20 M CF4
are placed in a container. At equilibrium, it is found that the [COF2] is 0.080 M. What is
the value of Keq?
A. 0.12
B. 1.5
C. 8.0
D. 3.0
30. Consider the following equilibrium: CH4(g) + H2O(g) ⇌ CO2(g) + 3H2(g) Keq =
5.67
An equilibrium mixture of this system was found to contain the following concentrations:
[CH4] = 0.59 M , [H2O] = 0.63 M, [CO2] = 0.25 M.
What was the equilibrium [H2] ?
A. 0.26 M
B. 0.64 M
C. 2.0 M
D. 8.4 M
31. Consider the following equilibrium: 2COF2(g) ⇌ CO2(g) + CF4(g)
Initially, 0.32 M CO2 and 0.40 M CF4 are placed in a container. At equilibrium, it is found
that the [COF2] is 0.16 M.
What is the value of Keq?
A. 0.026
B. 1.5
C. 9.3
D. 3.0
32. Consider the following equilibrium: CCl4(g) ⇌ C(s) + Cl2(g)
Initially, 0.62 mol CCl4 was placed in a 2.0L container.
At equilibrium, [Cl2] = 0.060 M. Which of the following is the value of Keq?
A. 0.00039
B. 0.24
C. 0.014
D. 0.78
33. Consider the following equilibrium: 2COF2(g) ⇌ CO2(g) + CF4(g)
Initially, 0.16 M CO2 and 0.20 M CF4 are placed in a container.
At equilibrium, it is found that the [COF2] is 0.080 M.
What is the value of Keq?
A. 0.12
B. 1.5
C. 8.0
D. 3.0
Equilibrium Quiz # 5 Calculations and Trial Keq Answers
1. Consider the following equilibrium: N2(g) + O2(g) ⇄ 2NO(g) Keq = 0.010
Initially, a 1.0 L container is filled with 0.40 mol of N2, 0.10 mol of O2 and 0.080 mol of
NO.
As the system approaches equilibrium, the
A. [NO], [N2] and [O2] remain unchanged
B. [NO] increases and both [N2] and [O2] decrease
C. [NO] decreases and both [N2] and [O2] increase
D. [NO] decreases and both [N2] and [O2] remain unchanged
2. Consider the following equilibrium: 2O2(g) + N2(g) ⇄ N2O4(g)
When 2.0 mol of O2 and 3.0 mol of N2 were placed in a 10.0 L container at 25oC, the
value of Keq=0.90.
If the same number of moles of reactant were placed in a 5.0 L container at 25oC, the
equilibrium constant would be
A. 0.011
B. 0.45
C. 0.90
D. 1.80
3. Consider the following equilibrium system: H2O(g) + CO(g) ⇄ H2(g) + CO2(g)
Initially, 5.0 moles of H2O and 4.0 moles of CO were reacted. At equilibrium, it is found
that 2.0 moles of H2 are present. How many moles of H2O remain in the mixture?
A. 1.0 moles
B. 2.0 moles
C. 3.0 moles
D. 4.0 moles
4. Consider the following equilibrium: PCl5(g) ⇄ PCl3(g) + Cl2(g) Keq=33.3
Predict what will occur when 2.0 mol of PCl5, 3.0 mol of PCl3 and 4.0 mol of Cl2
are placed in a 1.0 L container and allowed to establish equilibrium.
A. [PCl5] will increase
B. [PCl3] and [CL2] will both increase
C. [PCl5] and [Cl2] will both increase
D. [PCl5] and [PCl3] will both decrease
5. Consider the following equilibrium: CO(g) + 2H2(g) ⇄ CH3OH(g) ∆H= -18kJ
In order to increase the value of Keq for this reaction, you could
A. Increase [CO]
B. Increase the volume
C. Decrease [CH3OH]
D. Decrease the temperature
6. Consider the following: SO2Cl2(g) ⇄ SO2(g) + Cl2(g)
A 1.0 L container is initially filled with 2.0 mol of SO2Cl2.
As the reaction proceeds towards equilibrium, the rate of the forward reaction
A. Increases and the [SO2] increases
B. Increases and the [SO2] Decreases
C. Decreases and the [SO2] increases
D. Decreases and the [SO2] decreases
7. Consider the following: 2NO2(g) ⇄ N2O2(g) Keq=1.20
A 1.0 L of flask is filled with 1.4 mol NO2 and 2.0 mol N2O4.
To reach equilibrium, the reaction proceeds to the
A. Left as Trial Keq > Keq
B. Left as Trial Keq < Keq
C. Right as Trial Keq > Keq
D. Right as Trial Keq < Keq
8. Consider the following: 2C(s) + O2(g) ⇄ 2CO(g)
A 1.0 L flask is initially filled with 2.00 mol C and 0.500 mol O2.
At equilibrium, the [O2] is 0.250 mol/L. The Keq value is
A. 0.444
B. 1.00
C. 2.00
D. 2.25
9. Consider the following: 2H2O(g) ⇄ 2H2(g) + O2(g)
When 0.1010 mol H2O is placed in a 1.000 L container, equilibrium is established.
The equilibrium concentration of O2 is 0.0010 mol/L. the equilibrium concentrations of
H2O and H2 are
[H2O] [H2]
A 0.0990 0.0020
B 0.1000 0.0010
C 0.1005 0.0005
D 0.1010 0.0020
10. Which of the following equilibrium systems most favors the products?
A. Cl2(g) ⇄ 2Cl(g) Keq=6.4 x 10-39
B. Cl2(g) + 2NO(g) ⇄ 2NOCl(g) Keq=3.7 x 108
C. Cl2(g) + 2NO2(g) ⇄ 2NO2Cl(g) Keq=1.8
D. 2HCl(g) ⇄ H2(g) + Cl2(g) Keq=2.0 x 10-3
11. Consider the following equilibrium: H2O(g) + Cl2O(g) ⇄ 2HOCl(g) Keq= 9.0 x 10-2
A 1.0 L flask contains a mixture of 1.8 x 10-1 mol H2O. 4.0 x 10-4 mol Cl2O, and 8.0 x 10-2
mol HOCl .
To establish equilibrium, the system will proceed to the
A. Left as Trial Keq > Keq
B. Left as Trial Keq < Keq
C. Right as Trial Keq > Keq
D. Right as Trial Keq < Keq
12. Consider the following equilibrium: 2O3(g) ⇄ 3O2(g) Keq=55
If 0.060 mol of O3 and 0.70 mol of O2 are introduced into a 1.0 L vessel, the
A. Ktrial > Keq and the [O2] increases
B. Ktrial < Keq and the [O2] increases
C. Ktrial > Keq and the [O2] decreases
D. Ktrial < Keq and the [O2] decreases
13. Consider the following equilibrium: CO(g) + Cl2(g) ⇄ COCl2(g)
At equilibrium, a 2.0 L sample was found to contain 1.00 mol CO, 0.500 mol Cl2
and 0.100 mol COCl2. The Keq value for the above system is
A. 0.40
B. 0.20
C. 2.5
D. 5.0
14 Consider the following equilibrium: 2SO2(g) + O2(g)⇄ 2SO3(g) Keq=4.0
In an experiment, 0.40 mol SO2(g), 0.20 mol O2(g) and 0.40 mol SO3(g) are placed into a
1.0 liter container. Which of the following statements relates the changes in [SO2] and
[O2]
as equilibrium becomes established?
A. The [SO2] and [O2] increase
B. The [SO2] and [O2] decrease
C. The [SO2] and [O2] do not change
D. The [SO2] increases and the [O2] decreases
15. Consider the following equilibrium system: H2(g) + S(s) ⇄ H2S(g)
In a 1.0 L container at equilibrium there are 0.050 mol H2, 0.050 mol S and 1.0 mol H2S.
The value of Keq is
A. 2.5 x 10-3
B. 5.0 x 10-2
C. 2.0 x 101
D. 4.0 x 102
16. Consider the following equilibrium and experimental data:
N2O4(g) ⇄ 2NO2(g)
Initial Equilibrium
[N2O4] [NO2] [N2O4] [NO2]
Trial 1 0.0400 M 0.0000 M 0.0337 M 0.0125 M
Trial 2 0.0200 M 0.0600 M 0.0429 M 0.0141 M
Which of the following represents the Keq value?
A. 0.00464
B. 0.371
C. 0.742
D. 216
17. Consider the following equilibrium: Cl2(g) + 2NO(g) ⇌ 2NOCl(g) Keq = 5.0
At equilibrium, [Cl2] = 1.0 M and [NO] = 2.0 M.
What is the [NOCl] at equilibrium?
A. 0.80 M
B. 0.89 M
C. 4.5 M
D. 10 M
18. Consider the following equilibrium: Cl2(g) + 2NO(g) ⇌ 2NOCl(g)
If 12.0 moles of Cl2, 10.24 moles of NO, and 2.00 moles NOCl are placed in a
2.00 L container and the system moves to the right to get to equilibrium,
If there are 10.0 moles NOCl at equilibrium, calculate the Keq.
A. 0.996
B. 5.58
C. 1.12
D. 4.98
19. What will cause the value of Keq for an exothermic reaction to decrease?
A. increasing the pressure
B. increasing the temperature
C. decreasing the temperature
D. decreasing the surface area
20. Consider the following: H2(g) + I2(g) ⇌ 2HI(g)
Initially, some HI is placed into a 1.0 L container. At equilibrium there are 0.010 mol H2,
0.010 mol I2 and 0.070 mol HI present. How many moles of HI were initially added to
the container?
A. 0.060 mol
B. 0.070 mol
C. 0.080 mol
D. 0.090 mol
21. Consider the following equilibrium: 3NO2(g) ⇌ N2O5(g) + NO(g).
Initially, some NO2, N2O5 and NO were placed in a container and allowed to reach
equilibrium.
When equilibrium was established, it was found that the pressure had increased.
Which of the following explains what happened?
A. Trial Keq > Keq so the system shifted left.
B. Trial Keq < Keq so the system shifted left.
C. Trial Keq > Keq so the system shifted right.
D. Trial Keq < Keq so the system shifted right.
22. Consider the following equilibrium: 3NO2(g) ⇌ N2O5(g) + NO(g).
Initially, 8.00 moles NO2 were placed in a 2.0 L container and allowed to reach
equilibrium.
The equilibrium concentration of NO was 1.10 M. Calculate the Keq.
A. 1.7
B. 1.9
C. 3.5
D. 0.050
23. Consider the following equilibrium: 3NO2(g) ⇌ N2O5(g) + NO(g).
At a different temperature, 4.00 M NO2 were placed in a 2.0 L container and
allowed to reach equilibrium. The equilibrium concentration of NO2 was 1.00 M.
Calculate the Keq.
A. 0.11
B. 1.0
C. 3.0
D. 10.
24. Consider the reaction: 2HBr(g) ⇌ H2(g) + Br2(g) Keq = 49.0
If 4.0 M HBr is initially placed into a container, what will be the equilibrium [HBr]?
A. 0.27 M
B. 3.7 M
C. 5.3 M
D. 8.8 M
25. Consider the reaction: 2HBr(g) ⇌ H2(g) + Br2(g) Keq = 49.0
If 0.120 M H2, 0.120 M Br2 and 0.01714 M HBr are placed into a container at
440 C, which of the following is true as equilibrium is approached?
A. [Br2] decreases significantly.
B. [HBr] decreases significantly.
C. [H2] decreases significantly.
D. [H2] remains the same.
26. Consider the reaction: 2HBr(g) ⇌ H2(g) + Br2(g) Keq = 49.0
If 1.20 M H2, 1.20 M Br2 and 1.00 M HBr are placed into a container at
440 C, which of the following is true as equilibrium is approached?
A. [Br2] decreases significantly.
B. [HBr] decreases significantly.
C. [H2] decreases significantly.
D. [H2] remains the same.
27. Which Keq is most likely to favour the formation of reactants?
A. Keq = 1.65 x 104
B. Keq = 5.69 x 10-11
C. Keq = 3.95 x 10-11
D. Keq = 7.67 x 104
28. Which Keq is most likely to favour the formation of products?
A. Keq = 1.65 x 10-4
B. Keq = 5.69 x 10-11
C. Keq = 3.95 x 10-11
D. Keq = 7.67 x 10-4
29. Consider the following equilibrium system: 2NO(g) + Cl2(g) ⇌ 2NOCl(g) + 25 kJ
In which direction will the equilibrium shift and what happens to the value of Keq
when the temperature of the system is increased?
Shift Keq
A. right increases
B. right decreases
C. left increases
D. left decreases
30. Consider the following equilibrium system: 2NO(g) + Cl2(g) ⇌ 2NOCl(g) + 25 kJ
In which direction will the equilibrium shift and what happens to the value of Keq when
NO is added?
Shift Keq
A. right increases
B. right constant
C. left increases
D. left constant
31. Consider the following equilibrium: 2COF2(g) ⇌ CO2(g) + CF4(g)
Initially, 0.32 M CO2 and 0.40 M CF4 are placed in a container. At equilibrium, it is
found that the [COF2] is 0.16 M.
What is the value of Keq?
A. 0.026
B. 1.5
C. 9.3
D. 3.0
32. Consider the following equilibrium: CCl4(g) ⇌ C(s) + Cl2(g)
Initially, 0.62 mol CCl4 was placed in a 2.0L container.
At equilibrium, [Cl2] = 0.060 M. Which of the following is the value of Keq?
A. 0.00039
B. 0.24
C. 0.014
D. 0.78
33. Consider the following equilibrium: 2COF2(g) ⇌ CO2(g) + CF4(g) Initially, 0.16 M
CO2 and 0.20 M CF4 are placed in a container. At equilibrium, it
is found that the [COF2] is 0.080 M.
What is the value of Keq?
A. 0.12
B. 1.5
C. 8.0
D. 3.0
Equilibrium Quiz #6 Enthalpy and Entropy Answers
1. In which of the following reactions does the tendency towards minimum enthalpy and
maximum entropy oppose each other?
A. 3O3(g) ⇄ 2O2(g) ΔH = +285KJ
B. 1/2O2(g) + O2(g) ⇄ NO2(g) ΔH = +34KJ
C. 2H2O(g) ⇄ 2H2(g) + O2(g) ΔH = +484KJ
D. P4(s) + 6H2(g) ⇄ 4PH3(g) ΔH = +37KJ
2. In which of the following systems will the factors of entropy and enthalpy both favour
the reactants.
A. 3C(s) + 3H2(g) +heat ⇄ C3H6(g)
B. PCl5(g) + heat ⇄ PCl3(g) + Cl2(g)
C. NH4Cl(s) + heat ⇄ NH4+(aq) + Cl-(aq)
D. Cl2(g) + 2HI(g) ⇄ I2(g) + 2HI(g) + heat
3. For an exothermic reaction at equilibrium, an increase in temperature will cause the
equilibrium to shift
A. left and the Keq increases
B. left and the Keq decreases
C. right and the Keq increases
D. right and the Keq decreases
4. Consider the following equilibrium: COCl2(g) ⇄ CO(g) + Cl2(g) Keq = 8.1 x 10-4
For the above system,
A. [COCl2] < [CO][Cl2]
B. [COCl2] = [CO][Cl2]
C. [COCl2]> [CO][Cl2]
D. [COCl2] = 1/[CO][Cl2]
5. The value of the equilibrium constant will change when
A. a catalyst is used
B. temperature changes
C. product concentrations change
D. the volume of a gaseous system changes
6. In an exothermic equilibrium reaction involving only gases, the value of the Keq can be
decreased by
A. adding some reactant gas
B. removing some reactant gas
C. increasing the temperature
D. decreasing the temperature
7. Consider the following: H2(g) + CO2(g) ⇄ CO(g) + H2O(g) ΔH = +41KJ
The temperature of the above equilibrium system is increased while kept at a constant
volume.
A new state of equilibrium is established in which there is
A. an increase in [CO] and a decrease in Keq
B. an increase in [CO] and a increase in Keq
C. an increase in [CO2] and a decrease in Keq
D. an increase in [CO2] and a increase in Keq
8. Consider the following equilibrium: 2NO2(g) ⇄ N2O4(g) + 59KJ
For the above reaction,
A. both minimum enthalpy and maximum entropy favour the products.
B. both minimum enthalpy and maximum entropy favour the reactants.
C. minimum enthalpy favours reactants and maximum entropy favours products.
D. minimum enthalpy favours products and maximum entropy favours
reactants.
9. In which of the following does entropy decrease?
A. NaCl(s) → Na+(aq) + Cl-(aq)
B. 4NO(g) + 6H2O(g) → 4NH3(g) + 5O2(g)
C. 2NaCHCO3(s) → Na2CO3(s) + CO2(g) + H2O(g)
D. CaCO3(s) + HCl(aq) → CaCl2(aq) + CO2(g) + H2O(l)
10. Consider the following possible reaction: N2O(g) + NO2(g) → 3NO(g) + 120 KJ
Which of the following statements is correct?
A. Minimum enthalpy and maximum entropy both favour the products.
B. Minimum enthalpy and maximum entropy both favour the reactants.
C. Minimum enthalpy favours the reactants and maximum entropy favours the
products.
D. Minimum enthalpy favours the products and maximum entropy favours the
reactants.
11. Consider the following equilibrium: COCl2(g) ⇄ CO(g) + Cl2(g)
At equilibrium in a 1.0L container, there are 3.0 mol COCl2, 0.49 mol CO, and 0.49 mol
Cl2.
At constant temperature the volume of the above system is decreased to 0.50L. When
equilibrium is reestablished the
A. concentrations of all three gases have increased
B. concentrations of all three gases have decreased
C. [COCl2] has increased and [CO] and [Cl2] have decreased
D. [COCl2] has decreased and [CO] and [Cl2] have increased
12. Chemical systems move toward positions of
A. minimum enthalpy and maximum entropy
B. maximum enthalpy and minimum entropy
C. constant enthalpy and constant entropy
D. maximum enthalpy and maximum entropy
13. Consider the equilibrium: H2(g) ⇄ 2H(g) Keq = 1.2 x 10-71
The value of the equilibrium constant for the above system indicates that
A. the reaction rate is very slow
B. the equilibrium is exothermic
C. reactants are favoured in this equilibrium
D. a catalyst is necessary to establish equilibrium
14. Consider the following reaction:
Na2CO3(s) + HCl(aq) → 2NaCl(aq) + CO2(g) + H2O(l) ΔH = -27.7 KJ
In this reaction,
A. Minimum enthalpy and maximum entropy both favour the products.
B. Minimum enthalpy and maximum entropy both favour the reactants.
C. Minimum enthalpy favours the products and maximum entropy favours the
reactants.
D. Minimum enthalpy favours the reactants and maximum entropy favours the
products.
15. In an endothermic equilibrium system, the
A. Minimum enthalpy and maximum entropy both favour the products.
B. Minimum enthalpy and maximum entropy both favour the reactants.
C. Minimum enthalpy favours the products and maximum entropy favours the
reactants.
D. Minimum enthalpy favours the reactants and maximum entropy favours the
products.
16. Which of the following describes how a Keq value is related to the relative
concentrations of reactants and products?
Keq value Relative Concentration
I. large [products] > [reactants]
II. large [reactants] > [products]
III. small [products] > [reactants]
IV. small [reactants] > [products]
A. I only
B. IV only
C. I and IV only
D. II and III only
17. Consider the following equilibrium: N2(g) + O2(g) ⇌ 2NO(g) + 25.6 kJ
Under certain conditions, Keq = 0.00056. When conditions are changed,
Keq becomes 0.0256. Which of the following could account for this?
A. [N2] was changed.
B. A catalyst was added.
C. Temperature was decreased.
D. Temperature was increased.
18. Consider the following equilibrium: N2O(g) + NO2(g) ⇌ 3NO(g) + 120 KJ
Under certain conditions, Keq = 2.5. When conditions are changed, Keq becomes 0.15.
Which of the following could account for this?
A. [N2O] was added.
B. A catalyst was added.
C. Temperature was decreased.
D. Temperature was increased.
19. Reacting systems tend toward which of the following?
Entropy Enthalpy
A. minimum maximum
B. minimum minimum
C. maximum minimum
D. maximum maximum
20. Consider the following equation: NH4NO3(g) ⇌N2O(g) + 2H2O(g) + 37 kJ
Which of the following is true?
Enthalpy Favours Entropy Favours Outcome
A. reactants reactants does not occur
B. products products completion
C. reactants products equilibrium
D. products reactants equilibrium
21. Consider: energy + N2O4(g) ⇄ 2NO2(g)
The system above reaches equilibrium. Considering enthalpy and entropy factors,
which of the following is true with respect to the forward reaction?
A. The entropy is increasing and the reaction is exothermic.
B. The entropy is decreasing and the reaction is exothermic.
C. The entropy is increasing and the reaction is endothermic.
D. The entropy is decreasing and the reaction is endothermic.
22. Which of the following forward reaction changes would result in the most products?
Entropy Enthalpy
A. decreasing decreasing
B. increasing decreasing
C. decreasing increasing
D. increasing increasing
23. Which of the following forward reaction changes would result in the most reactants?
Entropy Enthalpy
A. decreasing decreasing
B. increasing decreasing
C. decreasing increasing
D. increasing increasing
24. Which of the following forward reaction changes would result equilibrium?
Entropy Enthalpy
A. decreasing decreasing
B. increasing decreasing
C. decreasing increasing
D. constant constant
25. When the temperature of an endothermic equilibrium is increased, which of the following
will happen?
A. Equilibrium will shift left and [products] will increase.
B. Equilibrium will shift left and [products] will decrease.
C. Equilibrium will shift right and [reactants] will increase.
D. Equilibrium will shift right and [reactants] will decrease.
26. When the temperature of an exothermic equilibrium is decreased, which of the following
will happen?
A. Equilibrium will shift left and [products] will increase.
B. Equilibrium will shift left and [products] will decrease.
C. Equilibrium will shift right and [reactants] will increase.
D. Equilibrium will shift right and [reactants] will decrease.
27. When the temperature of an endothermic equilibrium is increased, which of the following
will happen?
A. Equilibrium will shift left and the Keq will increase.
B. Equilibrium will shift right and the Keq will increase.
C. Equilibrium will shift left and the Keq will stay constant.
D. Equilibrium will shift right and the Keq will stay constant.
28. Consider: 2Li(s) + H2O(l) ® 2LiOH(aq) + H2(g) ΔH = -256 kJ?
What will entropy and enthalpy factors favour?
Entropy Enthalpy
A. products reactants
B. products products
C. reactants reactants
D. reactants products
29. Consider: 3C(s) + 3H2(g) + heat ⇄ C3H6(g)
What will entropy and enthalpy factors favour?
Entropy Enthalpy
A. products reactants
B. products products
C. reactants reactants
D. reactants products
30. In order for a chemical reaction to go to completion, how must the entropy and enthalpy
change?
enthalpy entropy
A. increases increases
B. increases decreases
C. decreases increases
D. decreases decreases
Acids Quiz #2 Conjugates, Reactions, Amphiprotic, Arrhenius, Bronsted Bases, KB, & Strength
Answers
1. A test that could be safely used to distinguish a strong base from a weak base is
A. taste
B. touch
C. litmus paper
D. electrical conductivity
2. Identify the two substances that act as Bronsted-Lowry bases in the equation
HS- + SO42- ⇄ S2- + HSO4-
A. HS- and S2-
B. SO4 2-and S2-
C. HS- and HSO4-
D. SO42- and HSO4-
3. The conjugate acid of H2C6H5O-7 is
A. C6H5O73-
B. HC6H5O72-
C. H2C6H5O7
D. H3C6H5O7
4. Which one of the following substances is/are amphiprotic?
(1) H3PO4 (2) H2PO4- (3) HPO42-
A. 2 only
B. 3 only
C. 1 and 2
D. 2 and 3
5. The net ionic equation for the neutralization of HBr by Ca(OH)2 is
A. H+(aq) + OH-(aq) ® H2O(l)
B. Ca2+(aq) + 2Br-(aq) ® CaBr2(s)
C. 2HBr(aq) + Ca(OH)2(aq) ® 2H2O(l) + CaBr2(s)
D. 2H+(aq) + Ca(OH)2(aq) ® 2H2O(l) + Ca2+(aq)
6. If reactants are favored in the following equilibrium, the stronger base must be
HCN + HS - ⇄ H2S + CN -
A. H2S
B. HS-
C. CN-
D. HCN
7. The hydronium ion, H3O+ is a water molecule that has
A. lost a proton
B. gained a proton
C. gained a neutron
D. gained an electron
8. The complete ionic equation for the neutralization of acetic acid by sodium
hydroxide is
A. H+ + OH- ⇄ H2O
B. CH3COOH + OH- ⇄ CH3COOH- + H2O
C. CH3COOH + NaOH ⇄ NaCH3COOH + H2O
D. CH3COOH + Na+ + OH- ⇄ Na+ + CH3COO- + H2O
9. In the following Bronsted – Lowry acid-base equation:
NH4+ (aq) + H2O(l) ⇄ NH3(aq) + H3O+(aq)
The stronger base is
A. NH4+
B. H2O
C. NH3
D. H3O+
10. Consider the following equilibrium system:
OCl-(aq) + HC7H5O2(aq) ⇄ HOCl(aq) + C7H5O2-(aq) Keq= 2.1 x 103
At Equilibrium
A. products are favored and HOCl is the stronger acid
B. reactants are favored and HOCl is the stronger acid
C. products are favored and HC7H5O2 is the stronger acid
D. reactants are favored and HC7H5O2 is the stronger acid
11. In the equilibrium system
H2BO3- (aq) + HCO3-(aq) ⇄ H2CO2(aq) + HBO32-(aq)
The two species acting as Bronsted-Lowry acids are
A. HCO3- and H2CO3
B. H2BO3- and H2CO3
C. HCO3- and HBO32-
D. H2BO3- and HBO32-
2. Consider the following equilibrium HS- + H2C2O4 ⇄ HC2O4- + H2S
The stronger acid is
A. HS-
B. H2C2O4
C. HC2O4-
D. H2S
13. Which species is not amphiprotic?
A. H2O
B. H3BO3
C. HPO42-
D. HC6H5O72-
14. Given the equilibrium: H2BO3- + H2PO4- ⇌ H3BO3 + HPO42-
Which is the strongest acid?
A. H2PO4-
B. H3BO3
C. HPO42-
D. H2BO3-
15. Which equation represents the reaction of a Brønsted-Lowry base with water?
A. 2Na + 2H2O ® 2NaOH + H2
B. P2H4 + H2O ⇌ P2H5+ + OH-
C. H2PO4- + H2O ⇌ H3O+ + HPO42-
D. H2C2O4 + H2O ⇌ H3O+ + HC2O4-
16. A definition for a Brønsted-Lowry acid should contain which of the following
phrases?
A. the donation of H+
B. the donation of OH-
C. the acceptance of H+
D. the acceptance of OH-
17. Which of the following would be a typical pH of soda pop?
A. 1.0
B. 3.2
C. 6.8
D. 7.2
18. When three 25.0 mL samples of the strong acid H2SO4 were titrated with 0.25 M NaOH
the following results were obtained:
Volume of NaOH(aq) 47.2 mL 39.9 mL 40.1 mL
What is the concentration of the H2SO4 sample?
A. 0.20 M
B. 0.21 M
C. 0.40 M
D. 0.42 M
19. Which of the following is a common base found in drain cleaners?
A. baking soda
B. vinegar
C. milk of magnesia
D. sodium hydroxide
20. Identify the common acid found in the stomach.
A. benzoic acid
B. sulphuric acid
C. perchloric acid
D. hydrochloric acid
21. Which of the following solutions would typically show the greatest electrical
conductivity?
A. 1.0 M weak acid
B. 0.8 M weak base
C. 0.5 M strong acid
D. 0.1 M strong base
22. Which of the following are amphiprotic in aqueous solutions?
I. H3BO3 II. H2BO3- III. H3BO2- IV. BO33-
A. I only
B. IV only
C. I and II only
D. II and III only
23. Which of the following best describes an acidic solution?
Litmus Colour Reaction with Mg
A. red reaction
B. red no reaction
C. blue no reaction
D. blue reaction
24. What is the Ka expression for H3PO4 ?
A. Ka = [H+]3
[PO43-]
B. Ka = [H+]3
[H3PO4]
C. Ka = [H+][H2PO4-]
[H3PO4]
D. Ka = [H+][HPO42-]
[H3PO4]
25. What volume of 0.250 M KOH is required to titrate 0.00230 mol of the weak acid
H2C2O4 ?
A. 1.15 mL
B. 4.60 mL
C. 9.20 mL
D. 18.4 mL
26. What is the net ionic equation for the titration of H3PO4(aq) with Sr(OH)2(aq) ?
A. H+(aq) + OH- (aq) ® H2O(l)
B. 6H+(aq) + 6OH-(aq) ® 6H2O(l)
C. 2H3PO4(aq) + 3Sr2+(aq) + 6OH-(aq) ® Sr3(PO4)2(s) + 6H2O(l)
D. 6H+(aq) + 2PO43-(aq) + 3Sr2+(aq) + 6OH- (aq) ® 3Sr2+ + 2PO43-(aq) + 6H2O(l)
27. Which of the following is a piece of equipment typically used in acid-base
titrations?
A. burette
B. test tube
C. litmus paper
D. graduated cylinder
28. Water has the greatest tendency to act as an acid with which of the following?
A. Cl-
B. NO2-
C. H2PO4-
D. CH3COO-
29. Which net ionic equation best describes the reaction between NaOH and H2S?
A. H+(aq) + OH-(aq) ® H2O(l)
B. H2S(aq) + 2OH- ® 2H2O(l) + S2-(aq)
C. H2S(aq) + 2NaOH ® 2H2O(l) + Na2S(aq)
D. 2H+(aq) + S2-(aq) + 2NaOH(aq) ® 2H2O(l) + 2Na+(aq) + S2-(aq)
30. Which of the following is a general characteristic of Arrhenius acids?
A. They produce H+ in solution.
B. They accept an H+ from water.
C. They donate a proton.
D. They accept a proton.
31. Which of the following is a general characteristic of Bronstead acids?
A. They produce H+ in solution.
B. They accept an H+ from water.
C. They donate a proton.
D. They accept a proton.
32. Which of the following is a general characteristic of Arrhenius bases?
A. They produce OH- in solution.
B. They produce H3O+ in water.
C. They donate a proton.
D. They accept a proton.
33. Which of the following is a general characteristic of Bronstead base?
A. They produce H+ in solution.
B. They accept an H+ from water.
C. They donate a proton.
D. They accept a proton
Which of the following oxides will form the most acidic solution?
A. SO2
B. MgO
C. Na2O
D. Al2O3
2. Which one of the following salts will produce an acidic solution?
A. KBr
B. LiCN
C. NH4Cl
D. NaCH3COO
3. The balanced equation for the reaction between sodium oxide and water is
A. Na2O + H2O → 2NaOH
B. Na2O + H2O → 2NaH + O2
C. Na2O + H2O → 2Na + H2O2
D. Na2O + H2O → 2Na + H2 +O2
4. Normal rainwater is slightly acidic due to the presence of dissolved
A. methane
B. carbon dioxide
C. sulphur dioxide
D. nitrogen dioxide
5. Which of the following oxides would hydrolyze to produce hydroxide ions?
A. NO
B. SO2
C. Cl2O
D. Na2O
6. The approximate pH of “normal” rainwater is
A. 0
B. 6
C. 7
D. 8
7. Which of the following oxides would hydrolyze to produce hydronium ions?
A. CaO
B. SO2
C. MgO
D. Na2O
8. Which of the following gasses results in the formation of acid rain?
A. H2
B. O3
C. SO2
D. NH3
9. Consider the following acid base solution
HSO3- + HF ⇄ H2SO3 + F-
The order of Bronsted-Lowry acids and bases in this equation is
A. acid + base ⇄ acid + base
B. acid + base ⇄ base + acid
C. base + acid ⇄ base + acid
D. base + acid ⇄ acid + base
10. The conjugate acid of OH- is
A. H+
B. O2-
C. H2O
D. H3O+
11. Which of the following 0.10 M solutions will have the greatest electrical
conductivity?
A. HF
B. NH3
C. NaOH
D. C6H5COOH
12. The amphiprotic ion HSeO3- can undergo hydrolysis according to the following equations
HSeO3- + H2O ⇄ H2SeO3 + OH- Kb
HSeO3- + H2O ⇄ SeO32-+ H3O+ Ka
An aqueous solution of HSeO3- is found to be acidic. This observation indicates that when it is
added to water, HSeO3- behaves mainly as a
A. proton donor, and Kb is less than Ka
B. proton donor, and Kb is greater than Ka
C. proton acceptor, and Kb is less than Ka
D. proton acceptor, and Kb is greater than Ka
13. The Kb expression for HPO42- is
A. [PO43-][H3O+] B. [HPO42-][ OH - ]
[HPO42-] [H2PO4-]
C. [H2PO4-][ OH - ] D. [HPO42-][ H3O+]
[HPO42-] [PO43-]
14. Given the equilibrium: H2BO3- + H2PO4- ⇌ H3BO3 + HPO42-
Which is the strongest acid?
A. HPO42-
B. H3BO3
C. H2PO4-
D. H2BO3-
15. Which species is not amphiprotic?
A. H2O
B. H3BO3
C. H2PO4-
D. H2C6H5O7-
16. What is produced when CH3NH2 acts as a base in water?
A. CH3NH-
B. CH3NH3+
C. CH3NH2+
D. CH2NH2-
17. What species will form when H+ ions are in the presence of H2O molecules?
A. HO+
B. H2O+
C. H3O+
D. H2O2+
18. What is the conjugate acid of the base HAsO42-?
A. AsO43-
B. H2AsO4-
C. H4AsO4+
D. H3AsO4
19. Which solution will have the greatest electrical conductivity?
A. 0.50 M HCl
B. 0.10 M RbOH
C. 0.50 M K3PO4
D. 2.0 M C6H12O6
20. The following equilibrium favours the formation of products:
NH2OH + CH3NH2 ⇌ CH3NH- + NH3OH+
Which species is the strongest acid?
A. NH3OH+
B. NH2OH
C. CH3NH2
D. CH3NH-
21. Which of the following solutions would have the greatest [OH-]?
A. 0.1 M HCO3-
B. 0.1 M HPO42-
C. 0.1 M H2PO4-
D. 0.1 M CO32-
22. Which of the following amphiprotic ions will act predominantly as a base in
solution?
A. HSO3-
B. HSO4-
C. H2PO4-
D. HPO42-
23. Which is the strongest base?
A. Cl-
B. NO2-
C. HPO42-
D. CH3COO-
24. Water has the greatest tendency to act as an acid with which of the following?
A. Cl-
B. NO2-
C. HPO42-
D. CH3COO-
25. Water has the greatest tendency to act as a base with which of the following?
A. HF
B. H2CO3
C. H3PO4
D. CH3COOH
26. Which of the following will have the smallest Ka value?
A. HF
B. H2CO3
C. H3PO4
D. CH3COOH
27. Which of the following will have the smallest Kb value?
A. IO3-
B. NH3
C. CN-
D. HPO42-
28. What volume of 0.500 M NaOH is required to neutralize 25.0 mL 0.250 M HBr ?
A. 5.00 mL
B. 12.5 mL
C. 20.0 mL
D. 25.0 mL
29. Which of the following Ka values represents the acid that is strongest?
A. Ka = 2.8 x 10-18
B. Ka = 8.2 x 10-18
C. Ka = 4.4 x 10-22
D. Ka = 6.4 x 10-22
30. Which of the following Ka values represents the acid with the strongest conjugate
base?
A. Ka = 2.8 x 10-18
B. Ka = 8.2 x 10-18
C. Ka = 4.4 x 10-22
D. Ka = 6.4 x 10-22
Acids Quiz #4 Anhydrides, Hydrolysis Answers
1. Which of the following pairs of gases are primarily responsible for producing
“acid rain”?
A. O2 and O3
B. N2 and O2
C. CO and CO2
D. NO2 and SO2
2. Sodium potassium tartrate (NaKC4H4O6) is used to raise the pH of fruit during
processing. In this process, sodium potassium tartrate is being used as a/an
A. salt
B. acid
C. base
D. buffer
3. The net ionic equation for the hydrolysis of the salt, Na2S is
A. Na2S ⇄ 2Na+ + S2-
B. S2- + H2O ⇄ OH- + HS+
C. Na2S + 2H2O ⇄ 2NaOH + H2S
D. 2Na+ + S2- + 2H2O ⇄ 2Na+ + 2OH- + H2S
4. Which of the following solutions would be acidic?
A. sodium acetate
B. iron III chloride
C. sodium carbonate
D. potassium chloride
5. Consider the following salts:
I. NaF II. NaClO4 III. NaHSO4
Which of these salts, when dissolved in water, would form a basic solution?
A. I only
B. I and II only
C. II and III only
D. I, II and III
6. Which of the following, when dissolved in water, forms a basic solution?
A. KCl
B. NaClO4
C. Na2CO3
D. NH4NO3
7. Which of the following oxides forms a basic solution?
A. K2O
B. CO2
C. SO3
D. NO2
8. Which of the following is amphiprotic in water?
A. SO2
B. SO32-
C. HSO3-
D. H2SO3
9. Consider the following equilibrium expression
K= [H2S][ OH - ]
[HS-]
This expression represents the
A. Kb for H2S
B. Ka for H2S
C. Kb for HS-
D. Ka for HS-
10. The reaction of a strong acid with a strong base produces
A. A salt and a water
B. A base and an acid
C. A metallic oxide and water
D. A non-metallic oxide and water
11. Consider the following equilibrium:
CH3COOH(aq) + NH3(aq) ⇄ CH3COOH-(aq) ⇄ NH4+(aq)
The sequence of Bronsted-Lowry acids and bases is
A. acid, base, base, acid
B. acid, base, acid, base
C. base, acid, base, acid
D. base, acid, acid, base
12. The pH range of ‘acid rain’ is often
A. 3 to 6
B. 6 to 8
C. 7 to 9
D. 10 to 12
13. Water will act as a Bronsted-Lowry acid with
A. NH3
B. H2S
C. HCN
D. HNO3
14. Which of the following is a conjugate acid-base pair?
A. H3PO4 and PO43-
B. H2PO4- and PO43-
C. H3PO4 and HPO42-
D. H2PO4- and HPO42-
15. What is the net ionic equation for the hydrolysis of NH4Cl ?
A. NH4Cl ® NH4+ + Cl-
B. Cl- + H2O ⇌ HCl + OH-
C. NH4+ + H2O ⇌ H3O+ + NH3
D. NH4+ + H2O ⇌ NH5+ + OH-
16. What is the approximate pH of the salt NH4Cl?
A. 0.0
B. 5.0
C. 7.0
D. 9.0
17. Four samples of rain are collected from different geographic regions and the pH is
measured for each sample.
Sample pH
1 2.8
2 4.0
3 6.2
4 6.8
Which of the above samples would be classified as acid rain?
A. 1 only
B. 1 and 2
C. 1, 2 and 3
D. 1, 2, 3 and 4
18. Which of the following equations correctly represents the reaction of a metallic
oxide with water?
A. K2O + H2O ® 2KOH
B. SO3 + H2O ® H2SO4
C. Na2O + H2O ® Na2O2 + H2
D. NaOH + HCl ® NaCl + HOH
19. Which of the following equations describes the dissociation of the salt,
ammonium chloride, in water?
A. NH4Cl(s) ® NH4Cl(aq)
B. NH4+(aq) + Cl-(aq) ® NH4Cl(s)
C. NH4Cl(s) ® NH4+(aq) + Cl-(aq)
D. NH4+(aq) + H2O(l) ® H3O+(aq) + NH3(aq)
20. Which of the following salt solutions is acidic?
A. NaBr
B. AlCl3
C. Li2CO3
D. NaHCO3
21. What pH would most likely result when CO2 dissolves naturally in rainwater?
A. 3.0
B. 6.6
C. 7.0
D. 7.5
22. Which of the following is the net ionic equation that describes the hydrolysis that
occurs in a K2CO3 solution?
A. K2CO3 ® 2K+ + CO32-
B. 2K+ + CO32- ® K2CO3
C. CO32- + H2O ® HCO3- + OH-
D. K2CO3 + 2H2O ® H2CO3 + 2KOH
23. What is the equilibrium expression for the predominant equilibrium in
NaCN(aq)?
A. Kb = [Na+][CN-]
[NaCN]
B. Kb = [Na+][CN-]
[HCN]
C. Kb = [HCN][OH-]
[CN-]
D. Kb = [CN-][OH-]
[HCN]
24. Which of the following salts will be basic?
A. KCl
B. NH4Cl
C. NaBr
D. Na2HPO4
25. Which of the following salts will be acidic?
A. KCl
B. NH4Cl
C. NaBr
D. Na2HPO4
26. Which is an acid anhydride?
A. Na2O
B. NaCl
C. CO2
D. NH4Cl
27. Which formula has the highest pH when in water?
A. Na2O
B. NaCl
C. CO2
D. NH4Cl
28. Which formula has the lowest pH when in water?
A. Na2O
B. NaCl
C. FeCl3
D. NaHCO3
29. Which formula has the lowest pH when in water?
A. NaCN
B. Na2HPO4
C. NH4Cl
D. NaOH
30. Which of the following properties is true for a solution of NaNO3 ?
A. It is neutral.
B. It is very basic.
C. It is slightly basic.
D. It is slightly acidic.
cids Quiz #5 pH calculations for Strong and Weak Acids Answers
1. The 1.0 M acidic solution with the highest pH is
A. H2S
B HNO2
C. HNO3
D. H3BO3
2. At 25 oC, the equation representing the ionization of water is
A H2O + H2O ⇄ 2H2 + O2
B. H2O + H2O ⇄ H2O2 + H2
C. H2O + H2O ⇄ 4H+ + 2O2-
D. H2O + H2O ⇄ H3O+ +OH-
3. The pH of a 0.3 M solution of NH3 is approximately
A. 14.0
B. 11.0
C. 6.0
D. 3.0
4. The pH of an aqueous solution is 4.32. The [OH-] is
A. 6.4 x 10-1 M
B. 4.8 x 10-5 M
C. 2.1 x 10-10 M
D. 1.6 x 10-14 M
5. The pH of an aqueous solution is 10.32. The [OH-] is
A. 5.0 x 10-12 M
B. 2.0 x 10-11 M
C. 4.8 x 10-11 M
D. 2.1 x 10-4 M
6. The pH of a 0.025 M HClO4 solution is
A. 0.94
B. 1.60
C. 12.40
D. 13.06
7. Consider the following equilibrium
H2O(l) ⇄ H2O(l) ⇄ H3O+(aq) + OH-(aq)
The equilibrium constant for this system is referred to as
A. Kw
B. Ka
C. Kb
D. Ksp
8. The [H3O-] in a solution of pH 0.60 is
A. 4.0 x 10-14 M
B. 2.2 x 10-1 M
C. 2.5 x 10-1 M
D. 6.0 x 10-1 M
9. A solution is prepared by adding 100 mL of 10 M of HCl to a 1 litre volumetric
flask and filling it to the mark with water. The pH of this solution is
A. -1
B. 0
C. 1
D. 7
10. The approximate pH of a 0.06 M solution of CH3COOH is
A. 1
B. 3
C. 11
D. 13
11. The [OH-] is greater than the [H3O+] in
A. HCl(aq)
B. NH3(aq)
C. H2O(aq)
D. CH3COOH(aq)
12. The pH of 0.15 M HCl is
A. 0.15
B. 0.71
C. 0.82
D. 13.18
13. Which of the following equations correctly relates pH and [H3O+] ?
A. pH= log [H3O+]
B. pH= 14 - [H3O+]
C. pH= -log [H3O+]
D. pH= pKw – [H3O+]
14. The pH of 0.20 M HNO3 is
A. 0.20
B. 0.63
C. 0.70
D. 1.58
15. The [OH-] in 0.050 M HNO3 at 25oC is
A. 5.0 x 10-16 M
B. 1.0 x 10-14 M
C. 2.0 x 10-13 M
D. 5.0 x 10-2 M
16. What is the approximate pH of a 1.0 M solution of the salt NH4Cl?
A. 0.0
B. 5.0
C. 7.0
D. 10.0
17. What is the approximate pH of a 1.0 M solution of the salt NH3?
A. 2.0
B. 5.0
C. 7.0
D. 10.0
18. What is the approximate pH of a 1.0 M solution of the salt NaHCO3?
A. 2.0
B. 5.0
C. 7.0
D. 9.0
19. What is the approximate pH of a 1.0 M solution of the salt AlCl3?
A. 0.0
B. 3.0
C. 7.0
D. 9.0
20. What is the approximate pH of a 1.0 M solution of the salt NaHSO4?
A. 0.0
B. 3.0
C. 7.0
D. 9.0
21. Which of the following is a definition of pH?
A. pH = +Log[H3O+]
B. pH = -Log[OH-]
C. pH = -Log[H3O+]
D. pH = pOH + pKw
22. What is the mass of NaOH required to prepare 100.0 mL of NaOH(aq) that has a
pH = 13.62 ?
A. 0.38 g
B. 0.42 g
C. 1.67 g
D. 0.14 g
23. What is the [KOH] in a KOH solution that has a pH =12.00?
A. 0.010 M
B. 0.56 M
C. 2.0 M
D. 2.0 x 10-12 M
24. What is the [H3O+] in 0.70 M HCN ?
A. 0.70 M
B. 1.9 x 10-5 M
C. 1.0 x 10-6 M
D. 2.4 x 10-10 M
25. What is the value of pKw for water at 25 0C ?
A. 10 x 10-14
B. 10 x 10-7
C. 7.00
D. 14.00
26. What pH would most likely result when CO2 dissolves naturally in rainwater?
A. 3.5
B. 6.5
C. 7.2
D. 7.8
27. What is the pOH of 0.05 M Ba(OH)2 ?
A. 1.0
B. 1.3
C. 12.7
D. 13.0
28. What is the pH of 0.5 M Sr(OH)2 ?
A. 0.0
B. 0.3
C. 12.7
D. 14.0
29. Which of the following statements is true for an acidic solution at 25 0C ?
A. pH > 7.0
B. pOH < 7.0
C. [H3O+] < [OH-]
D. [H3O+] > [OH-]
30. What is the [OH-] in 0.025 M HCl ?
A. 2.5 x 10-16 M
B. 4.0 x 10-13 M
C. 2.5 x 10-2 M
D. 1.6 M
The Kb for the dihydrogen phosphate ion is
A. 1.4 x 10-12
B. 6.3 x 10-8
C. 1.6 x 10-7
D. 7.1 x 10-3
2. What volume of 0.100 M NaOH is required to neutralize a 10.0 mL sample of 0.200 M
H2SO4?
A. 5.0 mL
B. 10.0 mL
C. 20.0 mL
D. 40.0 mL
3. Consider the following equilibria:
I HCO3- + H2O ⇄ H2CO3 + OH-
II NH4+ + H2O ⇄ H3O+ + NH3
III HSO3- + H3O ⇄ H2O + H2SO3
Water acts as a Bronsted-Lowry base in
A. III only
B. I and II only
C. II and III only
D. I, II, and III
4. Which of the following is represented by a Kb expression?
A. Al(OH)3(s) ⇄ Al3+(aq) + 3OH-(aq)
B. HF(aq) + H2O(l) ⇄ H3O+(aq) + F-(aq)
C. Cr2O72-(aq) + 2OH-(aq) ⇄ 2CrO42-(aq) + H2O(l)
D. CH3NH2(aq) + H2O(l) ⇄ CH3NH+3 (aq)
5. A student combines 0.25 mol of NaOH and 0.20 mol of HCl in water to make 2.0 liters
of solution. The pH of the solution is
A. 1.3
B. 1.6
C. 12.4
D. 12.7
6. If OH- is added to a solution, the [H3O+] will
A. Remain constant
B. Adjust such that [H3O+]= [OH - ]
Kw
C. Increase such that [H3O+][OH-] = Kw
D. Decrease such that [H3O+][OH-] = Kw
7. In a titration, 10.0 mL of H2SO4(aq) is required to neutralize 0.0400 mol of NaOH.
From this data, the [H2SO4] is
A. 0.0200 M
B. 2.00 M
C. 4.00 M
D. 8.00 M
8. Consider the following equilibrium for an acid-base indicator:
Hlnd ⇄ H+ + Ind- Ka = 1.0 x 10-10
Which of the following statements is correct at pH 7.0?
A. [Ind-] < [HInd]
B. [Ind-] = [HInd]
C. [Ind-] > [HInd]
D. [Ind-] = [H+] = [HInd]
9. Which of the following indicators would be yellow at pH 7 and blue at pH 10?
A. thymol blue
B. methyl violet
C. bromthymol blue
D. bromcresol green
10. Consider the following equilibrium for phenolphthalein: HInd + H+ + Ind-
When phenolphthalein is added to 1.0 M NaOH, the color of the resulting solution is
A. pink as [HInd] is less than [Ind-]
B. pink as [HInd] is greater than [Ind-]
C. colorless as [HInd] is less than [Ind-]
D. colorless as [HInd] is greater than [Ind-]
11. Water acts as a base when it reacts with
A. CN-
B. NH3
C. NO2-
D. NH4+
12. What is the pH of a solution prepared by adding 0.50 mol KOH to 1.0 L of 0.30 M
HNO3?
A. 0.20
B. 0.70
C. 13.30
D. 13.80
13. The 1.0 M acid solution with the largest [H3O+] is
A. HNO2
B. H2SO3
C. H2CO3
D. H3BO3
14. Consider the following indicator equilibrium:
HInd(aq) + H2O(l) ⇌ H3O+ + Ind-(aq)
Colourless blue
What is the effect of adding HCl to a blue sample of this indicator?
Equilibrium Shift Colour Change
A. left less blue
B. left more blue
C. right less blue
D. right more blue
15. Consider the following indicator equilibrium:
HInd(aq) + H2O(l) ⇌ H3O+ + Ind-(aq)
Colourless blue
What is the effect of adding NaOH to a light blue sample of this indicator?
Equilibrium Shift Colour Change
A. left less blue
B. left more blue
C. right less blue
D. right more blue
16. Consider the following indicator equilibrium:
HInd(aq) + H2O(l) ⇌ H3O+ + Ind-(aq)
yellow blue
What is the effect of adding FeCl3 to a green sample of this indicator?
Equilibrium Shift Colour Change
A. left yellow
B. left blue
C. right less blue
D. right more blue
17. An indicator has a Ka = 4 x 10-6. Which of the following is true for this indicator?
pH at Transition Point Indicator
A. 4.0 methyl orange
B. 4.0 bromcresol green
C. 5.4 methyl red
D. 5.4 bromcresol green
18. An indicator has a Ka = 6.3 x 10-13. Which of the following is true for this indicator?
pH at Transition Point Indicator
A. 4.0 methyl orange
B. 4.0 bromcresol green
C. 12.2 alizarin yellow
D. 12.2 indigo carmine
19. A salt forms in the reaction between HF(aq) and NaOH(aq). What is the net ionic equation
for the hydrolysis of this salt?
A. NaF(aq) ® Na+(aq) + F-(aq)
B. HF(aq) + H2O(l) ⇌ H3O+(aq) + F-(aq)
C. F-(aq) + H2O(aq) ⇌ HF(aq) + OH-(aq)
D. HF(aq) + NaOH(aq) ® NaF(aq) + H2O(l)
20. What is the Ka for the indicator that is yellow in its basic form and blue in its acid form?
A. 6 x 10-13
B. 2 x 10-9
C. 2 x 10-7
D. 3 x 10-5
21. What term is used to describe the point at which a chemical indicator changes colour?
A. titration point
B. transition point
C. equivalence point
D. stoichiometric point
22. What is the net ionic equation in the reaction between HF(aq) and NaOH(aq)?
A. NaF(aq) ® Na+(aq) + F-(aq)
B. HF(aq) + OH- (aq) ⇌ F-(aq) + H2O(l)
C. F-(aq) + H2O(aq) ⇌ HF(aq) + OH- (aq)
D. HF(aq) + NaOH(aq) ® NaF(aq) + H2O(l)
23. Consider the ionization of water: 2H2O ⇌ H3O+ + OH-
What happens to the pH when KOH is added to water?
A. pH increases since [H3O+] increases.
B. pH increases since [H3O+] decreases.
C. pH decreases since [H3O+] increases.
D. pH decreases since [H3O+] decreases.
24. Which of the following salt solutions is acidic?
A. NaBr
B. FeCl3
C. LiCN
D. NaHCO3
25. Which of the following salt solutions is neutral?
A. NaBr
B. FeCl3
C. LiCN
D. NaHCO3
26. What happens to the ion concentrations in water when a small amount of HBr(aq) is
added?
A. [H3O+] = [OH-] = 1.0 x 10-7 M
B. [H3O+] and [OH-] both increase
C. [H3O+] increases and [OH-] decreases
D. [H3O+] increases and [OH-] is unchanged
27. What is the Kb value for H2PO4- ?
A. 1.3 x 10-12
B. 6.2 x 10-8
C. 1.6 x 10-7
D. 2.5 x 103
28. What is one of the Ka values for thymol blue?
A. 2 x 10-9
B. 2 x 10-7
C. 1 x 10-7
D. 5 x 102
29. Consider the indicator equilibrium:
HInd(aq) + H2O(l) ⇌ H3O+ + Ind-(aq)
yellow blue
Which of the following is true about the transition point of this indicator?
A. pH = 7.0
B. [HInd] = [ Ind- ]
C. [HInd] > [ Ind- ]
D. moles of H3O+ moles of Ind-
30. What is the [OH-] in 0.25 M HCl ?
A. 2.5 x 10-15 M
B. 4.0 x 10-14 M
C. 2.5 x 10-1 M
D. Acid pH 2.5 x 10-13 M
X 4.0
Y 2.0phosphate ion, HPO
In water, the hydrogen
2-
4 , will act as
A. An acid because Ka < Kb
B. An acid because Ka > Kb
C. A base because Ka < Kb
D. A base because Ka > Kb
2. A student records the pH of 1.0 M solution of two acids
Which of the following statements can be concluded from the above data?
A. Acid X is stronger than acid Y
B. Acid X and acid Y are both weak
C. Acid X is diprotic while acid Y is monoprotic
D. Acid X is 100 times more concentrated than acid Y
3. When added to water, the hydrogen carbonate ion, HCO3-, produces a solution,
which is
A. basic because Kb is greater than Ka
B. basic because Ka is greater than Kb
C. acidic because Ka is greater than Kb
D. acidic because Kb is greater than Ka
4. The concentration, Ka and pH values of four acids are given in the following table
ACI Concentration Ka pH
D
HA 3.0 M 2.0 x 10-5 2.1
HB 0.7 M 4.0 x 10-5 2.3
HC 4.0 M 1.0 x 10-5 2.2
HD 1.5 M 1.3 x 10-5 2.4
Based on this data, the strongest acid is
A. HA
B. HB
C. HC
D. HD
5. Which of the following 0.10 M solutions is the most acidic?
A. AlCl3
B. FeCl3
C. CrCl3
D. NH4Cl
6. Which of the following acid-base indicators has a transition point between pH 7
and pH 9?
A. Ethyl red, Ka = 8 x 10-2
B. Congo red, Ka = 9.0 x 10-3
C. Cresol red, Ka = 1.0 x 10-8
D. Alizarin blue, Ka = 7.0 x 10-11
7. Which of the following would be a typical pH of lemon juice?
A. 1.0
B. 3.0
C. 6.8
D. 7.2
8. What is the [KOH] in a KOH solution that has a pH = 13.00?
A. 0.10 M
B. 0.56 M
C. 1.0 M
D. 1.0 x 10-13 M
9. What is the [H3O+] in 0.70 M HCN ?
A. 0.70 M
B. 1.9 x 10-5 M
C. 1.0 x 10-7 M
D. 3.4 x 10-10 M
10. The S2- ion is a base with an equilibrium constant of 0.77, what is the Ka value
for HS-?
A. 1.3 x 10-14
B. 9.1 x 10-8
C. 1.1 x 10-7
D. 7.7 x 1013
11. Which of the following is true as a result of the predominant hydrolysis of
NaHCO3?
Solution Reason
A. basic Ka > Kb
B. basic Ka < Kb
C. acidic Ka > Kb
D. acidic Ka < Kb
12. Consider the ionization of water: H2O + H2O ⇌ H3O+ + OH-
What happens to the pH when 0.1 M NaOH is added to water?
A. pH increases since [H3O+] increases.
B. pH increases since [H3O+] decreases.
C. pH decreases since [H3O+] increases.
D. pH decreases since [H3O+] decreases.
13. Which of the following amphiprotic ions will act predominantly as a base in
solution?
A. HSO3-
B. HSO4-
C. H2PO4-
D. HPO42-
14. Which of the following statements is true for a alkaline solution at 25 0C ?
A. pH < 7.0
B. pOH > 7.0
C. [H3O+] > [OH-]
D. [H3O+] < [OH-]
15. What is the [OH-] in 0.025 M HCl ?
A. 2.5 x 10-16 M
B. 4.0 x 10-13 M
C. 2.5 x 10-2 M
D. 2.5 x 10-12 M
16. Which of the following statements is true for an acidic solution at 25 0C ?
A. pH > 7.0
B. pOH < 7.0
C. [H3O+] < [OH-]
D. [H3O+] > [OH-]
17. What is the [H+] in 0.025 M NaOH?
A. 2.5 x 10-16 M
B. 4.0 x 10-13 M
C. 2.5 x 10-2 M
D. 2.5 x 10-12 M
18. What [H3O+] results when 25 mL of 1.0 M HCl is mixed with 10 mL of
2.0 M KOH ?
A. 0.70 M
B. 0.00 M
C. 0.10 M
D. 0.14 M
19. What is the pH of 0.70 M HCN ?
A. 0.70 M
B. 1.9 x 10-5 M
C. 5.32
D. 4.73
20. Consider the following indicator equilibrium:
HInd + H2O ⇌ H3O+ + Ind-
yellow blue
What is the result of adding FeCl3 to this indicator?
Equilibrium Shift Colour
A. left blue
B. left yellow
C. right blue
D. right yellow
21. An indicator changes colour when 1.0 M HCl is added. If the indicator has a
Ka = 1.0 x 10-10, determine the indicator and the pH at its transition point.
Indicator pH
A. phenolphthalein 4.0
B. phenolphthalein 10.0
C. thymolphthalein 4.0
D. thymolphthalein 10.0
22. What is the Kb value for HC6H5O72- ?
A. 1.0 x 10-14
B. 5.9 x 10-10
C. 2.4 x 10-8
D. 4.1 x 107
23. What is produced when MgO is added to water?
A. the metal Mg
B. the acid HMgO
C. the base Mg(OH)2
D. the amphiprotic species HMgO2
24. Which of the following is a major source of NO2(g), which contributes to
the problem of acid rain?
A. a smelter
B. an air conditioner
C. a nuclear power plant
D. the automobile engine
25. The indicator bromothymol blue can be described by the following equilibrium
equation:
HInd + H2O ⇌ H3O+ + Ind-
yellow blue
A base is added to the above indicator. After equilibrium has been re-established,
how do the H3O+ and the colour of the solution compare with the original
equilibrium?
H3O+ Colour of Solution
A. decreases turns blue
B. decreases turns yellow
C. increases turns blue
D. increases turns yellow
26. The indicator bromothymol blue can be described by the following equilibrium
equation:
HInd + H2O ⇌ H3O+ + Ind-
yellow blue
An acid is added to the above indicator. After equilibrium has been re-established,
how do the H3O+ and the colour of the solution compare with the original
equilibrium?
H3O+ Colour of Solution
A. decreases turns blue
B. decreases turns yellow
C. increases turns blue
D. increases turns yellow
27. What is the Ka value for the indicator neutral red?
A. 1 x 10-14
B. 4 x 10-8
C. 7.4
D. 14.0
28. What is a common source of SO2(g) ?
A. automobiles
B. a car battery
C. a lead smelter
D. oxidation of iron
29. What is the [H3O+] in 0.70 M HCN ?
A. 0.70 M
B. 1.9 x 10-5 M
C. 1.0 x 10-6 M
D. 2.4 x 10-10 M
30. What is the value of pKw for water at 25 0C ?
A. 1.0 x 10-14
B. 10 x 10-7
C. 7.00
D. 14.00
Consider the following acid solutions:
I. H2CO3 II. HClO4 III. HF
Which of the above acids would form a buffer solution when its conjugate base is added?
Solution 1.0 M HCl 1.0 M HAl 1.0 M HA2
Colour Yellow Blue Yellow
A. I only
B. II only
C. I and III only
D. I, II, and III only
2. Consider the following base indicator:
HInd ⇄ H+ + Ind-
When the indicator is added to different solutions, the following data are obtained:
The acids HAl, HA2, and HInd listed in the order of decreasing acid strength is
A. HA2, HInd, HAl
B. HInd, HAl, HA2
C. HA2, HAl, HInd
D. HAl, HInd, HA2
3. Which of the following compounds, when added to a solution of ammonium nitrate, will
result in the formation of a buffer solution?
A. Ammonia
B. Nitric acid
C. Sodium nitrate
D. Ammonium chloride
4. Which of the following represents a buffer equilibrium?
A. HI + H2O ⇄ H3O+ + I-
B. HCl + H2O ⇄ H3O + Cl-
C. HCN + H2O ⇄ H3O+ + CN-
D. HClO4 + H2O ⇄ H3O + ClO4-
5. Consider the following equilibrium:
HF(aq) + H2O(l) ⇄ H3O+(aq) + F-(aq)
The above system will behave as a buffer when the [F-] is approximately equal to
A. Ka
B. [HF]
C. [H2O]
D. [H3O+]
6. A basic buffer solution can be prepared by mixing equal numbers of moles of
A. NH4Cl and HCl
B. NaCl and NaOH
C. Na2CO3 and NaHCO3
D. NaCH3COO and CH3COOH
7. Which of the following would be used to prepare an acidic buffer solution?
A. HF and H3O+
B. NaHS and H2S
C. NH3 and NH4Cl
D. HCl and NaCl
8. HCN(aq) + H2O ⇌ H3O+(aq) + CN-(aq)
1.0 M 0.0001 M 0.0001 M
Why is the solution above not considered to be a true buffer solution?
A. excessive [HCN]
B. excessive [H3O+]
C. insufficient [CN-]
D. insufficient [HCN]
9. What could be added to 1.0 L of this solution in order for it to behave as a true buffer?
A. 1.0 mol HCl
B. 1.0 mol HCN
C. 1.0 mol H3O+
D. 1.0 mol NaCN
10. Which of the following could typically be used to prepare a buffer solution?
A. NaHS and H2S
B. H2S and Na2S
C. HNO3 and NaNO3
D. HNO3 and NaNO2
11. What happens to the pH of a buffer solution if a small amount of acid is added?
A. The pH remains constant.
B. The pH increases slightly.
C. The pH decreases slightly.
D. The pH decreases significantly.
12. Consider the following buffer equilibrium:
HF + H2O ⇌ H3O+ + F-
What concentration would limit the buffering action if acid were added?
A. [F-]
B. [HF]
C. [H2O]
D. [H3O+]
13. Consider the following buffer equilibrium:
HF + H2O ⇌ H3O+ + F-
What concentration would limit the buffering action if base were added?
A. [F-]
B. [HF]
C. [H2O]
D. [H3O+]
14. Which term does the following statement best describe? A mixture of a weak
acid and its conjugate base, each with distinguishing colours.
A. buffer
B. titration
C. indicator
D. conjugate
15. The HC2O4-(aq) ion will act as
A. a base since Ka > Kb
B. a base since Ka < Kb
C. an acid since Ka > Kb
D. an acid since Ka < Kb
16. What do a chemical indicator and a buffer solution typically both contain?
A. a strong acid and its conjugate acid
B. a strong acid and its conjugate base
C. a weak acid and its conjugate acid
D. a weak acid and its conjugate base
17. What is the approximate pH and Ka at the transition point for phenol red?
pH Ka
A. 6.0 6.3 x 10-7
B. 7.3 3.1 x 10-14
C. 7.3 5.0 x 10-8
D. 8.0 1.0 x 10-8
18. Which of the following acids could not be present in a buffer solution?
A. HF
B. HNO2
C. H2SO3
D. HCl
19. The indicator phenol red will be red in which of the following solutions?
A. 1.0 M HF
B. 1.0 M HBr
C. 1.0 M NH4Cl
D. 1.0 M NaHCO3
20. Which of the following chemical indicators has a Ka = 1.6 x 10-4 ?
A. methyl orange
B. phenolphthalein
C. thymolphthalein
D. bromcresol green
21. Which of the following chemical indicators has a Ka = 7.9 x 10-10 ?
A. methyl orange
B. phenolphthalein
C. thymolphthalein
D. bromcresol green
22. What is the Ka for phenolphthalein?
A. 1 x 10-14
B. 8 x 10-10
C. 1 x 109
D. 1.0 x 10-7
23. What volume of 0.250 M KOH is required to titrate 0.00230 mol of the weak
acid H2CO4 ?
A. 1.15 mL
B. 4.60 mL
C. 9.20 mL
D. 18.4 mL
24. What is the net ionic equation for the titration of H3PO4(aq) with Sr(OH)2(aq) ?
A. H+(aq) + OH- (aq) ® H2O(l)
B. 6H+(aq) + 6OH-(aq) ® 6H2O(l)
C. 2H3PO4(aq) + 3Sr2+(aq) + 6OH-(aq) ® Sr3(PO4)2(s) + 6H2O(l)
D. 6H+(aq) + 2PO43-(aq) + 3Sr2+(aq) + 6OH- (aq) ® 3Sr2+ + 2PO43-(aq) + 6H2O(l)
25. Which of the following will have the smallest Ka value?
A. HF
B. H2CO3
C. H3PO4
D. CH3COOH
26. Which of the following will have the smallest Kb value?
A. IO3-
B. NH3
C. CN-
D. HPO42-
27. What volume of 0.500 M NaOH is required to neutralize 25.0 mL 0.250 M HBr ?
A. 5.00 mL
B. 12.5 mL
C. 20.0 mL
D. 25.0 mL
28. Which of the following equations correctly represents the reaction of a metallic
oxide with water?
A. K2O + H2O ® 2KOH
B. SO3 + H2O ® H2SO4
C. Na2O + H2O ® Na2O2 + H2
D. NaOH + HCl ® NaCl + HOH
29. Which of the following equations describes the dissociation of the salt,
ammonium chloride, in water?
A. NH4Cl(s) ® NH4Cl(aq)
B. NH4+(aq) + Cl-(aq) ® NH4Cl(s)
C. NH4Cl(s) ® NH4+(aq) + Cl-(aq)
D. NH4+(aq) + H2O(l) ® H3O+(aq) + NH3(aq)
30. Which of the following salt solutions is acidic?
A. NaBr
B. AlCl3
C. Li2CO3
D. NaHCO3
Which of the following indicators would be used when titrating a weak acid with a strong base?
A. Methyl red
B. Methyl violet
C. Indigo carmine
D. Phenolphthalein
2. Which of the following acid-base pairs would result in an equivalence point with pH
greater than 7.0?
A. HCl and LiOH
B. HNO3 and NH3
C. HClO4 and NaOH
D. CH3COOH and KOH
3. Which of the following standardized solutions should a chemist select when
titrating a 25.00 mL sample of 0.1 M NH3, using methyl red as an indicator?
A. 0.114 M HCL
B. 6.00 M HNO3
C. 0.105 M NaOH
D. 0.100 M CH3COOH
4. Consider the following 0.100 M solutions
I. H2SO4 II. HCl III. HF
The equivalence point is reached when 10.00 mL of 0.100 NaOH has been added to
10.00 mL of solution(s)
A. II only
B. I and II only
C. II and III only
D. I, II and III
5.
Which pair of 0.10 M solutions would result in the above titration curve?
A. HF and KOH
B. HCl and NH3
C. H2S and NaOH
D. HNO3 and KOH
6. A suitable indicator for the above titration is
A. Methyl violet
B. Alizarin yellow
C. Thymolphthalein
D. Bromcresol green
7. The pH scale is
A. direct
B. inverse
C. logarithmic
D. exponential
8.
Which of the following indicators should be used in the titration represented by the above
titration curve?
A. Orange IV
B. Methyl red
C. Phenolphthalein
D. Alizarin yellow
9. Which of the following indicators should be used when 1.0 M HNO2 is titrated with
NaOH(aq)?
A. Methyl red
B. Thymol blue
C. Methyl orange
D. Indigo carmine
10. Which of the following solutions should be used when titrating a 25.00 mL sample of
CH3COOH that is approximately 0.1 M?
A. 0.150 M NaOH
B. 0.001 M NaOH
C. 3.00 M NaOH
D. 6.00 M NaOH
11. What volume of 0.250 M H2SO4 is required to neutralize 25.00 mL of 2.50 M KOH?
A. 125 mL
B. 150 mL
C. 250 mL
D. 500mL
12. Which of the following pairs of substances form a buffer system for human blood?
A. HCl and Cl-
B. NH3 and NH2-
C. H2CO3 and HCO3-
D. H2C6H5O7 and HC6H5O72-
13. What term is used to describe the point at which a chemical indicator changes
colour?
A. titration point
B. transition point
C. equivalence point
D. indicator point
14. What term is used to describe the point at which a the moles H+ equal the moles
OH- in a titration?
A. titration point
B. transition point
C. equivalence point
D. indicator point
15. Which of the following equations describes the predominant reaction that occurs
at the equivalence point of a titration between CH3COOH(aq) and NaOH(aq)?
A. H+(aq) + OH-(aq) ® H2O(l)
B. CH3COO-(aq) + H2O(l) ⇌ CH3COOH(aq) + OH-(aq)
C. CH3COOH(aq) + NaOH(aq) ® NaCH3COO(aq) + H2O(l)
D. CH3COO-(aq) + H2O(l) ⇌ CH2COO2-(aq) + H3O+(aq)
16. A salt forms in the reaction between HF(aq) and NaOH(aq). What is the net ionic
equation for the hydrolysis of this salt?
A. NaF(aq) ® Na+(aq) + F-(aq)
B. HF(aq) + H2O(l) ⇌ H3O+(aq) + F-(aq)
C. F-(aq) + H2O(l) ⇌ HF(aq) + OH-(aq)
D. F-(aq) + H2O(l) ⇌ H2F+(aq) + O2-(aq)
17. What is the pH in 0.10 M HCN ?
A. 7.0 x 10-6
B. 2.2 x 10-5
C. 4.65
D. 5.15
18. What volume of 0.250 M KOH is required to titrate 0.0200 mol of the weak acid
H2C2O4 ?
A. 160.0 mL
B. 40.0 mL
C. 20.0 mL
D. 10.0 mL
19. What is the approximate pH at the equivalence point when a weak acid is
titrated with a strong base?
A. pH = 9
B. pH = 5
C. pH = 7
D. pH = 14
20. What is the approximate pH at the equivalence point when a strong acid is
titrated with a weak base?
A. pH = 9
B. pH = 5
C. pH = 7
D. pH = 14
21. What term describes the chemical that is used to detect the end point of an acid-
base titration?
A. buffer
B. standard
C. indicator
D. primary standard
22. What term describes a solution of acid or base that can be prepared form a solid
an its concentration can be accurately calculated from the mass of the solid and
the volume of the volumetric flask.
A. buffer
B. standard
C. indicator
D. primary standard
23. Which of the titrations results in pH=7.0 at the equivalence point?
A. A weak acid is titrated with a weak base.
B. A weak acid is titrated with a strong base.
C. A strong acid is titrated with a weak base.
D. A strong acid is titrated with a strong base.
24. What is the pH of a solution prepared by adding 0.50 mol KOH to 1.0 L of
0.30 M HNO3?
A. 0.20
B. 0.70
C. 13.30
D. 13.80
25. A salt forms in the reaction between HF(aq) and NaOH(aq). What is the net ionic
equation for the hydrolysis of this salt?
A. NaF(aq) ® Na+(aq) + F-(aq)
B. HF(aq) + H2O(l) ⇌ H3O+(aq) + F-(aq)
C. F-(aq) + H2O(aq) ⇌ HF(aq) + OH-(aq)
D. HF(aq) + NaOH(aq) ® NaF(aq) + H2O(l)
26. What is the Ka for the indicator that is yellow in its basic form and blue in its acid
form?
A. 6 x 10-13
B. 2 x 10-9
C. 2 x 10-7
D. 3 x 10-5
27. The pH of an aqueous solution is 4.32. The [OH-] is
A. 6.4 x 10-1 M
B. 4.8 x 10-5 M
C. 2.1 x 10-10 M
D. 1.6 x 10-14 M
28. The pH of an aqueous solution is 10.32. The [OH-] is
A. 5.0 x 10-12 M
B. 2.0 x 10-11 M
C. 4.8 x 10-11 M
D. 2.1 x 10-4 M
29. The net ionic equation for the hydrolysis of the salt, Na2S is
A. Na2S ⇄ 2Na+ + S2-
B. S2- + H2O ⇄ OH- + HS+
C. Na2S + 2H2O ⇄ 2NaOH + H2S
D. 2Na+ + S2- + 2H2O ⇄ 2Na+ + 2OH- + H2S
30. Consider the following salts:
I. NaF II. NaClO4 III. NaHSO4
Which of these salts, when dissolved in water, would form a basic solution?
A. I only
B. I and II only
C. II and III only
D. I, II and III
Equilibrium Quiz # 1 Approaching Equilibrium Answers
1. Consider the following equilibrium: H2O(g) + CO(g) ⇄ H2(g) + CO2(g)
A closed container is initially filled with H2O and CO. As the reaction proceeds towards
equilibrium the
A. [CO] and [CO2] both increase
B. [ CO] and [CO2] both decrease
C. [CO] increases and [CO2] decreases
D. [CO] decreases and [CO2] increases
2. Consider the following equilibrium: 2SO3(g) ⇄ 2SO2(g) + O2(g)
At equilibrium, the rate of decomposition of SO3
A. Equals the rate of formation of O2
B. Equals the rate of formation of SO3
C. Is less than the rate of formation of O2
D. Is less than the rate of formation of SO3
3. Which of the following is true for all equilibrium systems?
A. The mass of reactants is equal to the mass of products
B. Addition of a catalyst changes the equilibrium concentrations
C. The concentration of reactants is equal to the concentration of products
D. The rate of the forward reaction is equal to the rate of the reverse reaction
4. Consider the following: 2NH3(g) ⇄ N2(g) + 3H2(g)
A flask is initially filled with NH3. As the system approaches equilibrium, the rate of the
forward reaction
A. Increases as the rate of the reverse reaction decreases
B. Decreases as the rate of the reverse reaction increases
C. Increases as the rate of the reverse reaction increases
D. Decreases as the rate of the reverse reaction decreases
5. A system at equilibrium is said to be dynamic because at equilibrium the
A. Temperature does not change
B. Macroscopic properties are constant
C. Forward and reverse reactions continue to occur
D. Concentrations of reactants and products are constant
6. In all systems at equilibrium, the
A. Concentration of reactants is less than the concentration of products
B. Concentration of reactants and the concentration of products are equal
C. Concentration of reactants is greater than the concentration of products
D. Concentration of reactants and the concentration of products are constant
7. Consider the following equilibrium: H2O(g) + CO(g) ⇄ H2(g) + CO2(g)
At high temperature, H2O and CO are placed in a closed container. As the system
approaches equilibrium, the
A. Rate of the forward and reverse reaction both increase
B. Rate of the forward and reverse reaction both decrease
C. Rate of the forward reaction decreases and the rate of the reverse reaction
increases
D. Rate of the forward reaction increases and the rate of the reverse reaction decreases
8. Which of the following statements are true for all equilibrium systems?
I. Macroscopic Properties are constant
II. Mass of the reactants equals mass of the products
III Equilibrium can be achieved from either products or reactants
A. I and II only
B. I and III only
C. II and III only
D. I, II, and III
9. Consider the following equilibrium: N2O4(g) + heat ⇄ 2NO2(g)
Initially, a 1.0 L container is filled with 2.0 mol of NO2. As the system approaches
equilibrium, the rate of reaction of NO2
A. Increases and [ N2O4 ] increases
B. Increases and [ N2O4 ] decreases
C. Decreases and [ N2O4 ] increases
D. Decreases and [ N2O4 ] decreases
10. Consider the following equilibrium: N2(g) + O2(g) ⇄ 2NO(g)
Nitrogen gas and oxygen react when placed in a closed container. As the reaction
proceeds towards equilibrium,
the rate of the reverse reaction
A. Increases as the concentration of products decreases
B. Decreases as the concentration of products decreases
C. Increases as the concentration of products increases
D. Decreases as the concentration of products increases
11. Consider the following
I Constant Temperature
II Equal concentrations of reactants and
products
III Equal rates of forward and reverse reactions
A system at equilibrium must have
A. I and II only
B. I and III only
C. II and III only
D. I, II , and III
12. Consider the following: N2O4(g) ⇌ 2NO2(g)
Colourless Brown
NO2 is placed in a flask at a constant temperature. Which of the following is true as the
system approaches equilibrium?
A. The colour gets darker as [NO2] increases.
B. The colour gets lighter as [NO2] decreases.
C. The colour gets darker as [N2O4] increases.
D. The colour gets lighter as [N2O4] decreases.
13. Consider the following: N2O4(g) ⇌ 2NO2(g)
Colourless Brown
N2O4 is placed in a flask at a constant temperature. Which of the following is true as the
system approaches equilibrium?
A. The colour gets darker as [NO2] increases.
B. The colour gets lighter as [NO2] decreases.
C. The colour gets darker as [N2O4] increases.
D. The colour gets lighter as [N2O4] decreases.
14. Consider the following equilibrium: PCl3(g) + Cl2(g) ⇌ PCl5(g)
If PCl5 is put in a container, how will the reaction rates change as the system approaches
equilibrium?
Forward Rate Reverse Rate
A. increases increases
B. increases decreases
C. decreases decreases
D. decreases increases
15. Consider the following equilibrium system: H2O(g) + CO(g) ⇌ CO2(g) + H2(g)
2.00 mole of CO2 and 2.00 mole of H2 are placed in a container and the system
approached equilibrium.
The following changes occur:
[CO2] [H2] [CO]
A. increases decreases decreases
B. increases increases decreases
C. decreases increases increases
D. decreases decreases increases
16. For the equilibrium system below:
Zn(s) + CuSO4(aq) ® Cu(s) + ZnSO4(aq)
We would know the system is at equilibrium because:
A. [Cu2+] = [Zn2+]
B. Cu(s) = Zn(s)
C. the mass of Cu(s) remains constant.
D. the mass of the entire system remains constant.
17. Which of the factors below is not a condition necessary for equilibrium?
A. a closed system
B. a constant temperature
C. equal forward and reverse reaction rates
D. equal concentrations of reactants and products
18. Products are placed in a beaker. How do the rates of the forward and reverse reactions
changes
the system proceeds to equilibrium?
Forward Rate Reverse Rate
A. increases increases
B. increases decreases
C. decreases increases
D. decreases decreases
19. Which of the factors below is not a condition necessary for equilibrium?
A. constant macroscopic properties
B. constant concentrations of reactant and product
C. equal forward and reverse reaction rates
D. a high activation energy
Drano®, a commercial product used to clean drains, contains small bits of aluminum metal and
A. ammonia
B. acetic acid
C. hydrochloric acid
D. sodium hydroxide
2. A net ionic equation for the reaction between CH3COOH and KOH is
A. CH3COOH(aq) + K+(aq) ⇄ CH3COOK(aq)
B. CH3COOH(aq) + OH-(aq) ⇄ H2O(l) + CH3COO-(aq)
C. CH3COOH(aq) + KOH(aq) ⇄ H2O(l) + CH3COOK(aq)
D. CH3COOH(aq) + K+(aq) + OH-(aq)⇄ H2O(l) + KCH3COO(aq)
3. Which equation represents a neutralization reaction?
A. Pb2+(aq) + 2Cl-(aq) → PbCl2(s)
B. HCl(aq) + NH3(aq) → NH4Cl(aq)
C. BaI2(aq) + MgSO4(aq) → BaSO4(s) + MgI2(aq)
D. MnO4-(aq) + 5Fe2+(aq) +8H+(aq) → Mn2+(aq) + 5Fe3+(aq) + 4H2O(l)
4. An Arrhenius acid is a substance that
A. accepts a proton
B. donates a proton
C. produces H+ in solution
D. produces OH- in solution
5. Consider the following data table:
Breaker Volume Contents
1 15 mL 0.1 M Sr(OH)2
2 20 mL 0.2 M NH4OH
3 25 mL 0.1 M KOH
4 50 mL 0.2 M NaOH
Identify the beaker that requires the smallest volume of 1.0 M HCl for complete
neutralization
A. Beaker 1
B. Beaker 2
C. Beaker 3
D. Beaker 4
6. The net ionic equation for the titration of HClO4(aq) with LiOH(aq) is
A. H+(aq) + OH-(aq) → H2O(l)
B. HClO4(aq) + OH-(aq) → ClO4-(aq) + H2O(l)
C. HClO4(aq) + LiOH(aq) → LiClO4(aq) + H2O(l)
D. H+(aq) + ClO4-(aq) + Li+(aq) + OH-(aq) → LiClO4(aq) + H2O(l)
7. The equilibrium constant expression for a sulphurous acid is
A Ka = [H+][HSO3-]
B. Ka = [H+][HSO3-]
[H2SO3]
C. Ka = [2H+][SO32-]
[H2SO3]
D. Ka = [H+][SO32-]
[H2SO3]
8. To distinguish between a strong acid and a strong base, an experimenter could use
A. odor
B. magnesium
C. a conductivity test
D. the common ion test
9. How many acids from the list below are known to be weak acids?
HCl, HF, H2SO3, H2SO4, HNO3, HNO2
A. 2
B. 3
C. 4
D. 5
10. There are two beakers on a laboratory desk. One beaker contains 1.0 M HCl and
the other contains tap water. To distinguish the acid solution from the water, one
would use
A. a piece of copper.
B. a piece of magnesium
C. phenolphthalein indicator
D. a piece or red litmus paper
11. Caustic soda, NaOH, is found in
A. fertilizers
B. beverages
C. toothpaste
D. oven cleaners
12. Which of the following is the strongest acid?
A. Acetic acid
B. Oxalic acid
C. Benzoic acid
D. Carbonic acid
13. The acid used in the lead-acid storage battery is
A. HCl
B. HNO3
C. H2SO4
D. CH3COOH
14. A definition for a Brønsted-Lowry acid should contain which of the following
phrases?
A. the donation of H+
B. the donation of OH-
C. the acceptance of H+
D. the acceptance of OH-
15. What species will form when H+ ions are in the presence of H2O molecules?
A. HO+
B. HO2+
C. H3O+
D. H2O2
16. What is the conjugate acid of the base HAsO42-?
A. AsO43-
B. H2AsO42-
C. H2AsO4-
D. H3AsO4
17. What species is the hydronium ion?
A. HO+
B. HO2+
C. H2O2
D. H3O+
18. Which of the following is a characteristic of acidic solutions?
A. They accept H+ ions.
B. They have a pH more than 7.
C. They react with Mg to produce H2 gas.
D. They turn limus blue.
19. Which of the following is a common base found in drain cleaners?
A. bleach
B. vinegar
C. milk of magnesia
D. sodium hydroxide
20. Which of the following is a characteristic of basic solutions?
A. They donate H+ ions.
B. They have a pH less than 7.
C. They feel slippery.
D. They turn limus red.
21. Which of the following is the weakest acid?
A. Acetic acid
B. Oxalic acid
C. Benzoic acid
D. Carbonic acid
22. What is the main difference between a strong acid and a weak acid?
A. their degree of ionization
B. their reactivity with platinum
C. their concentration in solution
D. their effect on an indicator
23. Which of the following best describes an acidic solution?
Litmus Colour Reaction with Zn
A. red reaction
B. red no reaction
C. blue no reaction
D. blue reaction
24. Identify the common acid found in the stomach.
A. benzoic acid
B. sulphuric acid
C. perchloric acid
D. hydrochloric acid
25. Which of the following best describes an basic solution?
Litmus Colour pH
A. red less than 7
B. red more than 7
C. blue less than 7
D. blue more than 7
26. Which of the following is a general characteristic of Arrhenius acids?
A. They produce H+ in solution.
B. They accept an H+ from water.
C. They turn bromothymol blue a blue colour.
D. They react with H3O+ ions to produce H2.
27. Identify a conjugate pair from the equilibrium provided:
PO43- + HCO3- ⇌ HPO42- + CO32-
A. CO32- and HPO42-
B. PO43- and HCO3-
C. PO43- and HPO42-
D. HCO3- and HPO42-
28. Which of the following best describes a weak acid?
A. pH = 10
B. It may be very soluble, but only partly ionized.
C. It must be very soluble and completely ionized.
D. It must be of low solubility and completely ionized.
29. Which of the following is a common property of acid solutions?
A. They have a pH > 7.
B. They turn red litmus blue.
C. They have a slippery feeling.
D. They turn pink phenolphthalein colourless.
30. What is a general characteristic of bases?
A. They all donate H+.
B. They all accept OH- .
C. They will neutralize acids
D. They will react with acids to produce H2 gas.
In a redox reaction, the species that loses electrons
A. is oxidized
B. is called the cathode
C. gains mass at the electrode
D. decreases in oxidation number
2. Which of the following is the strongest oxidizing agent?
A. Cu2+
B. Pb2+
C. Ni2+
D. Sn2+
3. Metallic platinum reacts spontaneously with Au3+(aq) but does not react with
Ag+(aq).
The metals, in order of increasing strength as reducing agents, are
A. Ag, Pt, Au
B. Pt, Au, Ag
C. Au, Ag, Pt
D. Au, Pt, Ag
4. The oxidizing agent in the above reaction is
A. Fe2+
B. Fe3+
C. Mn2+
D. MnO4-
5. MnO4- + 5Fe2+ + 8H+ → Mn2+ + 5Fe3+ + 4H2O
During the reaction, electrons transfer from
A. Fe3+ to Fe2+
B. Fe2+ to MnO4-
C. MnO4- to Fe2+
D. MnO4- to Mn2+
6. As an element is oxidized, its oxidation number
A. increases as electrons are lost
B. decreases as electrons are lost
C. increases as electrons are gained
D. decreases as electrons are gained
7. A solution of 1.0 M Pb(NO3)2 will not react with a container made of
A. Cu
B. Fe
C. Sn
D. Zn
8. A spontaneous redox reaction occurs when a piece of iron is placed in 1.0 M
CuSO4. The reducing agent is
A. Fe
B. Cu2+
C. H2O
D. SO42-
9. A substance is oxidized when it
A. loses protons
B. gains protons
C. loses electrons
D. gains electrons
10. A strip of titanium, Ti, is placed in 1.0 M Sn(NO3)2. The shiny surface of the
titanium darkens, indication that a reaction has
occurred. From this observation it may be concluded that
A. Ti2+ is a weaker reducing agent than Sn2+
B. Ti2+ is a weaker oxidizing agent than Sn2+
C. Ti2+ is a stronger reducing agent than Sn2+
D. Ti2+ is a stronger oxidizing agent than Sn2+
11. Consider the following redox reaction : Hg2+ + Cu → Hg + Cu2+ . In this
reaction, Hg2+ is a
A. weaker reducing agent than Cu2+
B. weaker oxidizing agent than Cu2+
C. stronger reducing agent than Cu2+
D. stronger oxidizing agent than Cu2+
12. The species which gains electrons in a redox reaction
A. loses mass
B. is oxidized
C. is the oxidizing agent
D. increases in oxidization number
13. Samples of Uranium, Vanadium and Yttrium (U, V, Y) were placed in solutions
containing the metallic ions U3+, V2+, and Y3+. The following observations were
recorded.
Trial Ion Metal Observation
1 U3+ Y reaction
2 V2+ U reaction
3 V2+ Y reaction
4 Y3+ V no reaction
The oxidizing agents from the strongest to the weakest are
A. V2+, U3+, Y3+
B. U3+, V2+, Y3+
C. Y3+, U3+, V2+
D. V2+, Y3+, U3+
14. Use the data below to answer the question.
Mo3+(aq) + Ir(s) ® no observable reaction
Ir3+(aq) + Nd(s) ® Nd3+(aq) + Ir(s)
Mo3+(aq) + Nd(s) ® Nd3+(aq) + Mo(s)
From these data it can be predicted that the oxidizing agents, listed from strongest
to weakest, are:
A. Ir3+ Mo3+ Nd3+
B. Mo3+ Nd3+ Ir3+
C. Ir3+ Nd3+ Mo3+
D. Mo Ir Nd
15. Which process could cause X2-(aq) to change to X+(aq)?
A. Z(s) ® Z3-(aq)
B. Z(s) ® Z3+(aq)
2-
C. Z (aq) ® Z+(aq)
D. Z3-(aq) ® Z(s)
16. In the reaction, what is the reducing agent?
4 Zn(s) + 10 H+(aq) + NO3-(aq) ® NH4+(aq) + 4 Zn2+(aq) + 3 H2O(l)
A. Zn(s)
B. H+(aq)
C. Zn2+(aq)
D. NO3-(aq)
17. A student observed the reactions between four different metals and the solutions
of their ions, and then recorded these 'spontaneous' reactions.
I. W(s) + X+(aq) ® W+(aq) + X(s)
+
II. X(s) + Y (aq) ® X+(aq) + Y(s)
III. Y(s) + Z+(aq) ® Y+(aq) + Z(s)
IV. X(s) + W+(aq) ® X+(aq) + W(s)
+
V. X(s) + Z (aq) ® X+(aq) + Z(s)
If equation I is correct, which equation did the student record incorrectly?
A. II
B. III
C. IV
D. V
18. The reaction below proceeds spontaneously.
A2+(aq) + X(s) ® A(s) + X2+(aq)
Elements A(s) and X(s) respectively, could be
A. Cr2+ and Co
B. Pb2+ and Cu
C. Co2+ and Cu
D. Ni2+ and Zn
19. A piece of Sn(s) was placed in the following solutions:
I. Cu(NO3)2(aq)
II. Hg(NO3)2(aq)
III. AgNO3(aq)
IV. Fe(NO3)2(aq)
A spontaneous reaction will occur in all solutions except
A. I
B. II
C. III
D. IV
20. Theoretically, a reducing agent can be described as a substance that
A. loses electrons and becomes reduced.
B. loses electrons and causes reduction.
C. gains electrons and causes oxidation.
D. gains electrons and becomes reduced.
21. In the reaction
Cu(s) + 2Ag+(aq) ® Cu2+(aq) + 2Ag(s)
A. Cu(s) is reduced by the oxidizing agent.
B. Ag+(aq) is the reducing agent and Cu(s) is reduced.
C. Cu(s) is the reducing agent and Ag+(aq) is reduced.
D. Cu(s) is the oxidizing agent and Ag+(aq) is oxidized.
22. Which of the following reactions is non-spontaneous?
A. I2(s) + Fe(s) ® 2I-(aq) + Fe2+(aq)
B. Ni2+(aq) + Sn2+(aq) ® Ni(s) + Sn4+(aq)
C. 2Li(s) + 2H2O(l) ® 2Li+(aq) + 2 OH-(aq) + H2(g)
D. 2Cl2(g) + 2 H2O(l) ® 4Cl-(aq) + O2(g) + 4H+(aq)
23. Which of the following best describes the process of oxidation?
A. the process in which oxygen is produced
B. the process in which electrons are added
C. the process in which the oxidation number decreases
D. the process in which the oxidation number increases
24. What is the oxidation number of N in the mercury (II) compound Hg(NH3)2Cl2
A. -6
B. -4
C. -3
D. +2
25. Which of the following combinations will react spontaneously under standard
conditions?
A. Ag + Br2
B. Ni + Co2+
C. Zn + Mg2+
D. Au + HNO3
26. Identify the substance that is oxidized in the following equation:
Br2 + SO2(g) + K2SO4 + 2H2O ® H2SO4 + 2KBr
A. Br2
B. SO2
C. H2O
D. K2SO4
27 What is the reducing agent in the following equation?
Fe2+ + 2I- ® Fe(s) + I2(s)
A. I2
B. I-
C. Fe2+
D. Fe3+
28. What is the oxidation number of C in the C3H5O2- ion ?
A. -1/3
B. -2/3
C. -1
D. -2
29. Which of the following best describes what happens when lead solid is placed in a
1.0 M solution of Cu(NO3)2?
A. The solution turns a darker blue.
B. No changes are observed.
C. Copper solid forms on the lead and the solution changes colour.
D. The mass of lead solid increases and the solution does not change colour.
30. Identify the reducing agent in the following equation:
Zn + 2MnO2 + H2O ⇌ Zn(OH)2 + 2MnO(OH)
A. Zn
B. H2O
C. MnO2
D. Zn(OH)2
Which of the following pairs of ions will react spontaneously in a solution?
A. Cu2+ and Fe2+
B. Pb2+ and Sn2+
C. Co2+ and Cr2+
D. Mn2+ and Cr2+
2. When NO2 reacts to form N2O4 the oxidation number of nitrogen
A. increases by 2
B. increases by 4
C. increases by 8
D. does not change
3. Consider the following redox equation:
12H+(aq) + 2IO3-(aq) + 10Fe2+(aq) → 10Fe3+(aq) + I2(s) + 6H2O(l)
The reducing agent is
A. I2
B. H+
C. Fe2+
D. IO3-
4. The oxidation number of nitrogen increases in
A. NO3- → NO
B. N2O4 → NI3
C. NH3 → NH4+
D. NO2 → N2O5
5. Which of the following represents a balanced reduction half-reaction?
A. VO2 + 2H+ + 2e- → V2+ + H2O
B. VO2 + H2 → V2+ + H2O + le-
C. VO2 + 2H+ + le- → V2+ + H2O
D. VO2 + 4H+ + 2e- → V2+ + 2H2O
6. Consider the following half reaction:
Sb2O3 + 6H+ + 6e- ⇄ 2Sb + 3H2O
The oxidation number of antimony in Sb2O3
A. increases by 3
B. increases by 6
C. decreases by 3
D. decreases by 6
7. Consider the following unbalanced half-reaction
HClO2 ⇄ HClO
The balanced half-reaction would have
A. 1 electron on the left
B. 1 electron on the right
C. 2 electrons on the left
D. 2 electrons on the right
8. The oxidation number of platinum in Pt(H2O)42+ is
A. +2
B. 0
C. +4
D. +1/2
9. Consider the following half-reaction :
BrO- → Br- (basic)
The balanced equation for the half-reaction is
A. BrO- + 2H+ + 2e- → Br- + H2O
B. BrO- + 2H+ → Br- + H2O + 2e-
C. BrO- + H2O → Br- + 2OH- + 2e-
D. BrO- + H2O + 2e- → Br- + 2OH-
10. Consider the following redox reaction:
2MnO4- + 5CH3CHO + 6H+ → 5CH3COOH + 2Mn2+ + 3H2O
The species that loses the electron is
A. H2O
B. MnO4-
C. CH3CHO
D. CH3COOH
11. Hydrogen has an oxidation number of –1 in
A. H2
B. NaH
C. H2O
D. KOH
12. Consider the following:
2NO3- + 4H+ + 2e- → N2O4 + 2H2O
This equation represents
A. reduction
B. oxidation
C. neutralization
D. decomposition
13. Which of the following half-reactions is balanced?
A. IO3- + 6H+ +5e- → I2 + 3H2O
B. IO3- + 6H+ + 4e- →1/2 I2 + 3H2O
C. IO3- + 6H+ → ½ I2 + 3H2O + 5e-
D. IO3- + 6H+ + 5e- → ½ I2 + 3H2O
14. Consider the following redox reaction:
Al + MnO4- + 2H2O →Al(OH)4- + MnO2
The chemical species being oxidized is
A. Al
B. MnO4-
C. Al(OH)4-
D. MnO2
15. Consider the following redox reaction:
6H+ + 6I- + ClO3- → 3I2 + 3H2O + Cl-
The reducing agent is
A. I-
B. I2
C. H+
D. ClO3-
16. Nitrogen has an oxidization number of zero in
A. N2
B. NO2
C. NH3
D. HNO3
17. When MnO4- reacts to form Mn2+, the manganese in MnO4- is
A. reduced as its oxidation number increases
B. reduced as its oxidation number decreases
C. oxidized as its oxidation number increases
D. oxidized as its oxidation number decreases
18. Consider the following reaction:
2HNO3 + 3H2S → 2NO + 3S + 4H2O
The nitrogen in HNO3 undergoes
A. reduction
B. oxidation
C. electrolysis
D. neutralization
19. The oxidation number in carbon in CaC2O4 is
A. +2
B. +3
C. +4
D. +6
20. Consider the following redox reaction:
2Cr3+(aq) + 3Cl2(aq) + 7H2O(l) → Cr2O72-(aq) + 6Cl-(aq) + 14H+(aq)
The species which loses electrons is
A. Cl2
B. Cr3+
C. H2O
D. Cr2O72-
21. Which equation represents a redox reaction?
A. Pb2+ + 2Cl- → PbCl2
B. CaO + CO2 → CaCO3
C. Mg + 2HCl → MgCl2 + H2
D. HCl + NaOH → NaCl + H2O
22. In a redox reaction, ClO- was converted to Cl- in a basic solution. The balanced
half-reaction for this process is
A. ClO- + H2O + 2e- → Cl- + 2OH-
B. ClO- + 2OH- → Cl- + 2e- + H2O
C. ClO- + H2O → Cl- + 2e- + 2OH-
D. ClO- + 2OH- + 2e- → Cl- + H2O
23. Which of the following equations is not predicted to represent a redox reaction?
A. 2 H2O(l) + O2(g) ® 2 H2O2(l)
B. 2 Sn (aq) ® Sn(s) + Sn4+(aq)
2+
C. Ag+(aq) + Cl-(aq) ® AgCl(s)
D. C2H4(g) + 3 O2(g) ® 2 CO2(g) + 2 H2O(g)
24. The metal molybdenum, Mo, can react to produce MoO2(s). The half reaction that explains
the change in oxidation state of
molybdenum can be written
A. Mo(s) + 2e- → Mo2+
B. Mo(s) → Mo2+ + 2e-
C. Mo4+ + 4e- → Mo(s)
D. Mo(s) → Mo4+ + 4e-
25. Which incomplete half-reaction is an oxidation?
A. 2H+ + 12 O2(g) → H2O(l)
B. Cr2O72- + 14H+ → 2 Cr3+ + 7 H2O(l)
C. K+ → K(s)
D. 2 I- → I2(s)
26. Which of these would react spontaneously with Co(s) but not with H2(g)?
A. H2O(l)
B. Ni2+(aq)
C. Ca2+(aq)
D. Br-(aq)
27. The chemical that will reduce copper (II) ions and also oxidize metallic nickel is
aqueous
A. iron (III) nitrate
B. tin (II) sulfate
C. iron (II) nitrate
D. zinc sulfate
28. F2(g) is a strong reducing agent F2(g) has a strong attraction for electrons. Based on this
information, one should determine that
A. the statement and the explanation are true, and that the explanation is
correct for the statement.
B. both the statement and the explanation are true, but the explanation is not
correct for the statement.
C. the statement is true, but the explanation is false.
D. the statement is false, but the explanation is true
29. Solutions containing Fe2+(aq), Sn2+(aq) and Cr2+(aq) are mixed together. The reaction
most likely to occur is
A. 2Fe2+(aq) + 2 H2O(l) ® Fe(s) + O2(g) + 4H+(aq)
B. Sn2+(aq) + 2Cr2+(aq) ® Sn(s) + 2 Cr3+(aq)
C. Sn2+(aq) + Cr2+(aq) ® Sn4+(aq) + Cr(s)
D. Sn2+(aq) + 2 Fe2+(aq) ® Sn(s) + 2 Fe3+(aq)
30. Four reducing agents listed in order of decreasing strength are W, Z, Y and X. Four
statements about the reaction
between the reducing agents and their respective oxidizing agents are:
I. W(s) + X2+(aq) ® W2+(aq) + X(s)
2+
II. Y(s) + X (aq) ® Y2+(aq) + X(s)
III. W(s) + Z2+(aq) ® no reaction
2+
IV. Y(s) + Z (aq) ® Y2+(aq) + Z(s)
The statement(s) inconsistent with the correct order of reducing agents is (are)
A. IV only
B. III only
C. I and II
D. III and IV
Consider the following overall reaction:
2Rh+ + Pb(s) → 2Rh(s) + Pb2+- E0 = 0.73 V
The E0 for the half-reaction Rh+ + e- ⇄ Rh is
A. -0.86 V
B. -0.60 V
C. +0.60 V
D. +0.86 V
2. Which of the following systems would be correct if the zinc half-cell would havebeen
chosen as
the standard instead of the hydrogen half-cell?
A. The reduction potentials of all the half-cells would remain unchanged
B. The reduction potentials of all the half-cells would increase by 0.76 V
C. The reduction potentials of all the half-cells would have positive values
D. The reduction potentials of the hydrogen half-cell decrease by 0.76 V
3. Three beakers contain 1.0 M CuCl2. A piece of metal is placed in each of the
beakers
BEAKER SOLUTION METAL
1 CuCl2 Zn
2 CuCl2 Ag
3 CuCl2 Ni
Reactions occur in
A beaker 2 only
B. beakers 1, 2, and 3
C. beakers 1 and 2 only
D. beakers 1 and 3 only
4. Consider the following redox reaction:
3SO2 + 3H2O + ClO3- → 3SO42- + 6H+ + Cl-
The reduction half-reaction is
A. ClO3- + 6H+ → Cl- + 3H2O + 6e-
B. ClO3- + 6H+ + 6e- → Cl - + 3H2O
C. SO2 + 2H2O → SO42- + 4H+ + 2e-
D. SO2 + 2H2O + 2e- → SO42- + 4H+
5. What two substances are produced when Cr and 1.0 M MnO4- react in a basic solution?
A. Mn2+ and Cr3+
B. MnO2 and Cr3+
C. Mn2+ and Cr2+
D. MnO2 and CrO42-
6. Bromine, Br2, will react spontaneously with
A. I-
B. I2
C. Cl-
D. Cl2
7. The substances H2O2, H3PO4 and H2SO3 in order of increasing strengths as
oxidizing agents are.
A H2O2, H3PO4, H2SO3
B. H2SO3, H3PO4, H2O2
C. H3PO4, H2SO3 , H2O2
D. H2O2,H2SO3 , H3PO4
8. Consider the following overall equation for an electrochemical cell:
3Ag+ + Cr → Cr3+ + 3Ag
At standard conditions ,the initial cell voltage is
A. +0.06 V
B. +0.39 V
C. +1.21 V
D. +1.54
9. A solution of 1.0 M Co(NO3)2 should be stored in a container made of
A. tin
B. zinc
C. aluminum
D. magnesium
10. A strong oxidizing agent has a
A. weak attraction for electrons
B. strong attraction for electrons
C. weak ability to become reduced
D. strong ability to become oxidized
11. The two species which react spontaneously in acidic solutions are
A. IO3- and I2
B. SO42- and S
C. BrO3- and Br -
D. AuCl4- and Au
12. Consider the following redox reaction:
Co2+(aq) + 2Ag(s) → 2Ag+(aq) + Co(s)
The reaction is
A. spontaneous and Eo is positive.
B. spontaneous and Eo is negative.
C. non-spontaneous and Eo is positive.
D. non-spontaneous and Eo is negative
13. Referring to the data booklet, which of the following can act as an oxidizing agent but not
as a reducing agent?
A. Zn
B. Cl-
C. Sn2+
D. Fe3+
14. Which equation represents a redox reaction?
A. Pb2+ + 2Cl- → PbCl2
B. CaO + CO2 → CaCO3
C. Mg + 2HCl → MgCl2 + H2
D. HCl + NaOH → NaCl + H2O
15. In a redox reaction, ClO- was converted to Cl- in a basic solution. The balanced half-
reaction for this process is
A. ClO- + H2O + 2e- → Cl- + 2OH-
B. ClO- + 2OH- → Cl- + 2e- + H2O
C. ClO- + H2O → Cl- + 2e- + 2OH-
D. ClO- + 2OH- + 2e- → Cl- + H2O
16. Which of the following gives the correct oxidation numbers for the nitrogen atoms
in all three chemical species?
N2 Li3N NO2-
A. 0 -3 +3
B. -3 -3 +3
C. 0 +3 -3
D. -3 -3 -3
17. The oxidation number of manganese changes as MnO4- is converted to MnO2How many
electrons are
gained or lost by the manganese during the change?
A. 1e- lost
B. 1e- gained
C. 3e- lost
D. 3e- gained
18. Which of the solutions listed below should NOT be stored in a tin-plated container?
I NaNO3(aq) II AgNO3(aq) III SnBr2(aq) IV Cl2(aq)
A. I only
B. II and IV
C. II, III and IV
D. II and III
19. If fluorine gas is bubbled through NaI(aq),
A. Na+(aq) is reduced
B. I-(aq) is oxidized
C. F2(aq) is oxidized
D. I-(aq) is reduced
20. A high school laboratory's waste container is used to dispose of aqueous
solutions of sodium nitrate, potassium sulfate, hydrochloric acid, and tin (II)
chloride. The most likely net redox reaction predicted to occur inside the waste
container is represented by the equation:
A. Sn2+(aq) + 2NO3-(aq) + 4H+(aq) ® 2NO(g) + 2H2O(l) + Sn4+(aq)
B. 2 H+(aq) + 2K+(aq) ® H2(g) + K(s)
C. SO42-(aq) + 4H+(aq) + 2 Cl-(aq) ® H2SO3(aq) + H2O(l) + Cl2(g)
D. Cl2(g) + Sn2+(aq) ® Cl-(aq) + Sn(s)
21. The net ionic equation for the reaction between aqueous solutions of tin (II)
bromide and iron (III) nitrate is
A. Sn2+(aq) + NO3-(aq) ® NO2(g) + Sn4+(aq)
B. Sn2+(aq) + 2 Fe3+(aq) ® Sn4+(aq) + 2 Fe2+(aq)
C. 2Sn2+(aq) + Fe3+(aq) ® 2 Sn3+(aq) + Fe2+(aq)
D. Sn2+(aq) + 2NO3-(aq) ® 2NO2(g) + Sn4+(aq
22. Use the following unbalanced redox reaction to answer this question.
__O2(g) + ___H+(aq) + ___Ag(s) ® __Ag+(aq) + ___H2O(l)
The coefficients for the balanced equation are
A. 1,4,4,4,2
B. 1,4,1,1,2
C. 1,2,1,1,1
D. 1,1,1,1,1
23. A student mixes various combinations of the metals Pd, Cd and Ga with 1.0 M
solutions of their ions. The student then measures the voltages and puts them in
the table below.
1 Ga Pd2+ +1.18 V
2 Ga Cd2+ +0.16 V
3 Cd Pd2+?
What voltage is produced by reaction # 3?
A. -1.34 V
B. -1.02 V
C. +1.02 V
D. +1.34 V
24. Which of the following is a correctly balanced reduction half-reaction?
A. 2HCN + 2e- ® C2N2 + 2H+
B. 2Sb + 3H2O + 6e- ® Sb2O3 + 6H+
C. NO3- + 3H+ + 3e- ® HNO2 + H2O
D. Sb2O5 + 6H+ + 4e- ® 2Sb(OH)2+ + H2O
25. Which of the following combinations will react spontaneously under standard
conditions?
A. Ag + Br2
B. Ni + Co2+
C. Zn + Mg2+
D. Au + HNO3
26. Which of the following best describes what happens when lead solid is placed in a
1.0 M solution of Cu(NO3)2?
A. Bubbles form on the lead.
B. No changes are observed.
C. Copper solid forms on the lead and the solution changes colour.
D. The mass of lead solid increases and the solution does not change colour.
27. Consider the following unbalanced equation for a redox reaction in acidic
solution: Br- + BrO3- ® Br2
What is the equation for the balanced reduction half-reaction?
A. 2Br- ® Br2 + 2e-
B. 2Br- + 2e- ® Br2
C. 5e- + 6H+ + 2BrO3- ® Br2 + 3H2O
D. 10e- + 12H+ + 2BrO3- ® Br2 + 6H2O
28. What reaction will occur when a solution containing 1.0 M MgSO4 and 1.0 M
CoCl2 is stored in a galvanized (Zn coated) bucket?
A. Mg(s) + Cl2 ® MgCl2(s)
B. Co2+ + SO42- ® CoSO4(s)
C. Co2+ + Zn(s) ® Zn2+ + Co(s)
D. Mg2+ + Zn(s) ® Zn2+ + Mg(s)
29. When the skeletal equation I- ® IO3- is balanced in acidic solution, H2O, H+
and e- will appear. Which of the following are the correct balancing coefficients?
H2O H+ e-
A. 3 3 2
B. 3 6 6
C. 3 6 5
D. 6 12 10
30. Consider the following balanced redox equation in acidic solution:
5H2O + 2CoCl2 + OCl- ® 2Co(OH)3 + 5Cl- + 4H+
Which of the following describes the amounts and locations of OH- and H2O if
the equation is balanced in basic solution?
A. 1H2O on the left and no OH-
B. 1H2O on the left and 4OH- on the left
C. 5H2O on the left and 4OH- on the left
D. 1H2O on the left and 4OH- on the right
Redox Quiz #4 Electrochemical Cells/Electrolytic Cells Answers
1. In the electrochemical call above, the electrons flow from
A. zinc to lead and the mass of zinc increases
B. zinc to lead and the mass of lead increases
C. lead to zinc and the mass of zinc increases
D. lead to zinc and the mass of lead increases
2. The initial cell voltage is
A. -0.89 V
B. -0.63 V
C. +0.63 V
D. +0.89 V
3. In an operating lead-zinc electrochemical cell shown above, the cathode
A. gains mass as anions are reduced
B. loses mass as anions are reduced
C. gains mass as cations are reduced
D. loses mass as cations are reduced
4. The equation for the half-reaction at the anode is
A. Zn2+ + 2e- → Zn
B. Pb2+ + 2e- → Pb
C. Zn → Zn2+ + 2e-
D. Pb → Pb2+ + 2e-
5. The equation for the half-reaction at the cathode is
A. Zn2+ + 2e- → Zn
B. Pb2+ + 2e- → Pb
C. Zn → Zn2+ + 2e-
D. Pb → Pb2+ + 2e-
6. The direction of electron flow in an electrochemical cell is from
A. anode to cathode through the external wire
B. cathode to anode through the external wire
C. anode to cathode through the external wire and back through the salt bridge
D. cathode to anode through the external wire and back through the salt bridge
7. Which of the following is formed at the anode during the electrolysis of 1.0 M NaI?
A. I2
B. O2
C. H2
D. Na
Molten MgCl2
8. As this cell operates
A. Cl- is oxidized at the anode
B. Mg2+ is oxidized at the anode
C. Cl- is oxidized at the cathode
D. Mg2+ is oxidized at the cathode
9. In an operating electrochemical cell, the anions migrate
A. towards the anode through the wire
B. towards the cathode through the wire
C. towards the anode through the salt bridge
D. towards the cathode through the salt bridge
10. As the above electrochemical cell operates
A. nitrate ions migrate into the copper half-cell
B. copper (II) ions migrate through the salt bridge
C. magnesium ions migrate through the salt bridge
D. potassium ions migrate into the magnesium half-cell
11. In the above electrochemical cell, the reaction at the anode is
A. Cu → Cu2+ + 2e-
B. Cu2+ + 2e- → Cu
C. Mg → Mg2+ + 2e-
D. Mg2+ + 2e- → Mg
12. In the above electrochemical cell, the initial voltage is
A. 2.03 V
B. 2.52 V
C. 2.71 V
D. 2.89 V
13. Which of the following aqueous solutions produces H2(g) and O2(g) during electrolysis
A. 1.0 M KI
B. 1.0 M CuI2
C. 1.0 M K2SO4
D. 1.0 M CuSO4
14. In the electrolysis of molten zinc chloride, the half-reaction at the anode is
A. Cl2 + 2e- → 2Cl-
B. 2Cl- → Cl2 + 2e-
C. Zn2+ 2e- → Zn
D. Zn → Zn2+ + 2e-
15. The initial cell voltage at 25oC is
A. -1.06 V
B. -0.54 V
C. +0.54 V
D. +1.06 V
16. The balanced equation for the overall reaction is
A. Ni+(aq) + Ag(s) → Ag+(aq) + Ni(s)
B. Ni(s) + Ag+(aq) → Ag(s) + Ni+(aq)
C. Ni2+(aq) + 2Ag(s) → 2Ag+(aq) + Ni(s)
D. Ni(s) + 2Ag+(aq) → 2Ag(s) + Ni2+(aq)
17. This redox reaction occurs because
A. Ag(s) is a stronger oxidizing agent than Ni(s)
B. Ag(s) is a weaker reducing agent than Ni(s)
C. Ag+(aq) is a stronger reducing agent than Ni2+(aq)
D. Ag+(aq) is a weaker oxidizing agent than Ni2+(aq)
18. The direction of the electron flow is
A. from Au to Pb through the wire
B. from Pb to Au from the wire
C. from Au to Pb through the salt bridge
D. from Pb to Au through the salt bridge
19. As the cell operates
A. NO3- and K+ will migrate toward the Pb half-cell
B. NO3- and K+ will migrate toward the Au half-cell
C. NO3- will migrate toward the Pb half-cell and K+ will migrate toward the Au
half-cell
D. NO3- will migrate toward the Au half-cell and K+ will migrate toward the Pb half-
cell
20. The initial voltage is
A. -1.37 V
B. 0.00 V
C. 1.37 V
D. 1.63 V
21. Which of the following is a balanced half-reaction in base?
A. Cl2 + 3H2O → ClO3- + 6H+ + 5e-
B. Cl2 + 6OH- → ClO3- + 5e- + 3H2O
C. Cl2 + 6H2O → 2ClO3- + 12H+ + 10e-
D. Cl2 + 12OH- → 2ClO3- + 6H2O + 10e-
22. In which of the following unbalanced equations does chromium undergo oxidation?
A. Cr3+ → Cr
B. Cr3+ → Cr2+
C. Cr3+ → Cr2O72-
D. CrO42- → Cr2O72-
23. Which of the following is formed at the anode and cathode during the electrolysis of
1.0 M Na2SO4?
Anode Cathode
A. O2 H2
B. H2 O2
C. H2 Na
D. S Na
24. Consider the electrolytic cell shown in the following diagram:
Which of the following describes the anion movement and electrode masses for the above
cell?
Anion Movement Mass of Pt Electrode Mass of Cu Electrode
A. to the Cu increases increases
B. to the Cu increases decreases
C. to the Pt decreases increases
D. to the Pt decreases decreases
25. Which of the following describes electrolysis?
A. a process that uses electrical energy to cause a spontaneous reaction
B. a process that generates electrical energy using a spontaneous reaction
C. a process that uses electrical energy to cause a non-spontaneous reaction
D. a process that generates electrical energy using a non-spontaneous reaction
26. What products would form at the anode and cathode as this cell operates?
Anode Cathode
A. I2 Ni
B. Ni I2
C. O2 H2
D. Cu2+ Ni
27. In the above cell, if 1.0 M NiI2 is replaced with molten NiI2, what products would form at
the electrodes?
Anode Cathode
A. I2 Ni
B. Ni I2
C. O2 H2
D. Cu2+ Ni
28. In the above cell, which describes the movement of the electrons?
A. They move from left to right towards the anode.
B. They move from right to left towards the anode.
C. They move from right to left towards the cathode.
D. They move from left to right towards the cathode.
29. Which of the following best describes what happens to the mass of the anode and the
mass of the cathode as the cell operates?
Anode Mass Cathode Mass
A. decreases increases
B. decreases no change
C. no change decreases
D. no change no change
30. What is the standard voltage E0 for the cell?
A. 0.43 V
B. 0.77 V
C. 1.34 V
D. 1.68 V
The corrosion of iron can be prevented by attaching a piece of zinc to the iron
because the
A. iron acts as an anode
B. zinc reduces more readily than iron
C. electrons flow from the zinc to the iron
D. iron ions form more readily than zinc ions
2. An iron spoon is electroplated with copper. The equation representing the
reduction reaction is
A. Cu2+(aq) + 2e- ® Cu(s)
B. Cu(s) ® Cu2+(aq) + 2e-
C. Fe2+(aq) + 2e- ® Fe(s)
D. Fe(s) ® Fe2+(aq) + 2e-
3. In an operating zinc-copper electrochemical cell, the oxidizing agent
A. loses electrodes at the anode
B. loses electrons to the cations
C. gains electrodes at the cations
D. gains electrons from the anions
4. An example of electro refining is the
A. extraction of aluminum from bauxite
B. purification of lead from an impure anode
C. recovery of zinc from a zinc sulphide solution
D. production of chlorine from a sodium chloride solution
5. Electroplating always involves the
A. oxidation of anions
B. reduction of cations
C. reduction at the anode
D. oxidation at the cathode
6. Hydrogen and oxygen react to provide energy in a
A. dry cell
B. fuel cell
C. alkaline cell
D. lead-acid storage cell
7. En electrolytic process is used to purify impure lead. The electrodes are
ANODE CATHODE
A. carbon impure lead
B. pure lead carbon
C. pure lead impure lead
D. impure lead pure lead
1.0 M CuSO4
8. The half-reaction at the cathode is
A. Cu2+ + 2e- → Cu(s)
B. 2SO42- → S2O82- + 2e-
C. H2O → ½ O2(g) + 2H+ + 2e-
D. 2H2O + 2e- → H2(g) + 2OH-
9. In the electrolysis of molten PbBr2 with inert electrodes, the products at the anode
and cathode are
Anode Cathode
A. Br2 H2
B. O2 Pb
C. Pb Br2
D. Br2 Pb
10. Under which conditions could an electrochemical cell provide 0.93V?
Anode Cathode
A. Cu Mg
B. Mg Cu
C. Ag Pb
D. Pb Ag
11. The reduction reaction in the above electrochemical cell is
A. Pb2+ + 2e- → Pb
B. Pb → Pb2+ + 2e-
C. Ag+ + e- → Ag
D. Ag → Ag+ + e-
12. An industrial process involving electrolysis is the reduction of
A. water forming oxygen gas
B. water forming hydrogen gas
C. sea water forming chlorine gas
D. sea water forming bromine liquid
13. To plate a nickel coin with copper
A. the nickel coin must be the cathode
B. the cathode must be made of copper
C. the electrons must flow to the anode
D. the solution must contain nickel ions
14. Which of the following ions can be reduced from an aqueous solution
A. Ba2+
B. Al3+
C. Sn2+
D. Na+
15. The principal function of a fuel cell is to
A. produce fuel
B. electrolyze fuel
C. produce hydrogen
D. produce electricity
16. If a piece of nickel is to be gold-plated using an electolytic process, which half-
reaction occurs at the cathode?
A. Ni → Ni2+ + 2e-
B. Ni2+ + 2e- → Ni
C. Au → Au3+ + 3e-
D. Au3+ + 3e- → Au
17. Consider the following redox reaction
AS2O3 + 2NO3- + 2H2O + 2H+ → 2H3AsO4 + N2O3
In this reaction, nitrogen
A. loses electrons and increases in oxidation number
B. gains electrons and increases in oxidation number
C. loses electrons and decreases in oxidation number
D. gains electrons and decreases in oxidation number
18. In an electrochemical cell, the cathode
A. is reduced
B. loses mass
C. is the reducing agent
D. is the site of reduction
19. When 1.0 M NaI is electrolyzed, bubbles of gas form on one electrode and a
reddish-brown substance forms on the other. The half-reaction at the cathode is
A. 2I- → I2 + 2e-
B. Na+ + e- → Na
C. H2O + ½ O2 + 2H+ + 2e-
D. 2H2O +2e- → H2 + 2OH-
20. Which of the following would prevent the corrosion of an iron nail?
A. Store the nail in acid.
B. Store the nail in dry air.
C. Store the nail in water.
D. Store the nail wrapped in nickel wire in a beaker of distilled water.
21. A student brought an old key to the Chemistry Lab to plate it with copper. He set
up a cell like the one in the following diagram:
1 M CuSO4
Which of the following combinations should produce the best result?
Object 1 Electron Flow Object 2
A. AC power supply towards the key Ag
B. DC power supply towards the key copper
C. DC power supply from the key copper
D. voltmeter from the key Pt
22. Which of the following occurs when a solution of NiF2 is electrolyzed using
inert carbon electrodes?
A. The cathode dissolves.
B. Hydrogen gas is produced.
C. The pH of the solution decreases.
D. The Ni2+ concentration increases.
23. What is the cathode reaction for this cell?
A. Na+ + e- ® Na
B. Br2 + 2e- + ® 2Br-
C. 2Br- ® Br2 + 2e-
1
D. H2O ® /2O2 + 2H+ + 2e-
24. Which of the following best describes the movement of sodium ions and
electrons as the cell operates?
Na+ Ion Movement Electron Movement
A. towards the Cu towards the Pt
B. towards the Cu towards the Cu
C. towards the Pt towards the Cu
D. towards the Pt towards the Pt
25. What is the standard cell voltage?
A. -075 V
B. +0.62 V
C. +0.75 V
D. +1.43 V
26. Which of the following is an example of corrosion?
A. iron spontaneously oxidizing
B. sulphur spontaneously oxidizing
C. iron reducing
D. sulphur non-spontaneously oxidizing
27. Consider the following equation:
Co + SO42- + 4H+ ⇌ Co2+ + H2SO3 + H2O
Which statement is correct?
A. The sulphur is oxidized and the cobalt is reduced.
B. The cobalt is oxidized and the sulphur is reduced.
C. The hydrogen is reduced and the cobalt is oxidized.
D. The hydrogen is reduced and the oxygen is oxidized.
28. Which of the following occurs during the electrolysis of molten KCl?
A. Oxygen forms at the anode.
B. Potassium forms at the anode.
C. Chlorine forms at the cathode.
D. Potassium forms at the cathode.
29. The above cell is constructed in order to nickel plate an object. For best results,
which of the following should be used for electrodes A and B?
Electrode A Electrode B
A. object pure nickel
B. pure nickel object
C. object any conductor
D. any conductor object
30. A student tries to use the above apparatus to nickel plate a zinc object. What will
happen if the student places the zinc object at A and the nickel electrode at B?
Electrode A Electrode B
A. Ni forms Ni dissolves
B. Zn dissolves Zn forms
C. Zn dissolves Ni forms
D. Bubbles form Bubbles form
Which of the following metals could be used to cathodically protect a sample of lead?
A. iron
B. gold
C. silver
D. copper
2. A piece of iron can be prevented from corroding by
A. making it a cathode
B. placing it in an acidic solution
C. attaching a small piece of lead to it
D. attaching a small piece of gold to it
3. To determine the [Fe2+] in a solution of FeSO4 by e redox titration, a suitable reagent would be
an acidified solution of
A. Cr3+
B. Mn2+
C. SO42-
D. Cr2O72-
4. As a metal corrodes,
A. it gains electrons
B. it becomes reduced
C. it acts as a reducing agent
D. its oxidation number decreases
5. Which method will cathodically protect a piece of iron?
A. Paint the iron
B. Cover the iron with grease
C. Attach a piece of lead tot he iron
D. Attach a piece of magnesium to the iron
6. Corrosion of iron can be prevented by attaching a piece of
A. Mn
B. Cu
C. Pb
D. Sn
7. A student attempted to determine the Eo (volts) of the following half-reaction:
Pd2+ + 2e- → Pd Pd2+ reacts with Cu(s) but not with Hg(l).
Based on the above, the Eo (volts) of a Pd half-cell is
A. less than 0.34 V
B. greater than 1.50 V
C. greater than 0.85 V but less than 1.50 V
D. greater than 0.34 V but less than 0.85 V
8.Consider the following redox equation:
Br2 + SO2 + Na2SO4 + 2H2O → 2H2SO4 + 2NaBr
Which of the following is gaining electrons?
A. Br2
B. SO2
C. H2O
D. Na2SO4
9. The reaction that occurs when pieces of lead, zinc, copper and silver are placed in a solution of
Ni(NO3)2 is
A. Pb + Ni2+ → Pb2+ + Ni
B. Zn + Ni2+ → Zn2+ + Ni
C. Cu + Ni2+ → Cu2+ + Ni
D. 2Ag + Ni2+ → 2Ag+ + Ni
10. In the electrochemical cell above, the electrons flow from
A. copper to lead through the wire
B. lead to copper through the wire
C. copper to lead through the salt bridge
D. lead to copper through the salt bridge
11. In the electrochemical cell above, the initial Eo value is
A. 0.03 V
B. 0.21 V
C. 0.29 V
D. 0.47 V
12. A reaction that occurs during the corrosion of iron is
A. Fe + 3e- → Fe3+
B. Fe → Fe2+ + 2e-
C. Fe2+ + 2e- → Fe
D. Fe3+ + e- → Fe2+
13. Consider the following reaction
Zn(s) + 2Ag+(aq) → Zn2+(aq) + 2Ag(s)
What volume of 0.500 M AgNO3 is required to react completely with 6.54 g of zinc?
A. 0.0131 L
B. 0.0262 L
C. 0.200 L
D. 0.400 L
14. Consider the following diagram:
Why would this cell fail to electroplate the Fe nail with copper?
A. The Cu is inert.
B. The Fe nail is the anode.
C. The Fe nail is the cathode.
D. The porous membrane prevents reaction.
15. Consider the following diagram:
Why would this cell fail to electroplate the Fe nail with copper?
A. The Cu is the cathode.
B. The electrolyte does not contain Cu2+.
C. The Fe nail is the cathode.
D. The porous membrane prevents reaction.
16. A 10.0 mL water sample was analyzed for [Fe2+] using a redox titration with
acidified KMnO4. The equation for the reaction is:
MnO4- + 5Fe2+ + +8H+ ® Mn2+ + 5Fe3+ + 4H2O
A 10.0 mL sample was titrated with 12.5 mL of 0.100 M KMnO4 solution.
What is the [Fe2+] in the water sample?
A. 0.025 M
B. 0.13 M
C. 0.28 M
D 0.63 M
17. Why is aluminum a good choice for the manufacture of outdoor structures?
A. Pure aluminum is easily reduced.
B. Pure aluminum is not easily oxidized.
C. Pure aluminum is easily reduced, but forms a protective coating.
D. Pure aluminum is easily oxidized, but forms a protective coating.
18. Which of the following are produced at the anode and the cathode during the
electrolysis of aqueous calcium iodide using carbon electrodes?
Anode Cathode
A. Iodine Calcium
B. Hydrogen Oxygen
C. Oxygen Hydrogen
D. Iodine Hydrogen
19. Which of the following are produced at the anode and the cathode during the
electrolysis of molten calcium iodide using carbon electrodes?
Anode Cathode
A. Iodine Calcium
B. Hydrogen Oxygen
C. Oxygen Hydrogen
D. Iodine Hydrogen
20. Which of the following are produced at the anode and the cathode during the
electrolysis of aqueous potassium fluoride using carbon electrodes?
Anode Cathode
A. Oxygen Potassium
B. Hydrogen Oxygen
C. Oxygen Hydrogen
D. Fluorine Potassium
21. Which of the following are produced at the anode and the cathode during the
electrolysis of molten potassium fluoride using carbon electrodes?
Anode Cathode
A. Oxygen Potassium
B. Hydrogen Oxygen
C. Oxygen Hydrogen
D. Fluorine Potassium
22. Two reactions involved in the refining of copper are:
Reaction I 2Cu2S + 3O2 ® 2Cu2O + 2SO2
Reaction II Cu2S + 2Cu2O ® 6Cu + SO2
What happens to the copper ions in this process?
A. They are reduced in Reaction I.
B. They are reduced in Reaction II.
C. They are oxidized in Reaction I.
D. They are oxidized in Reaction II.
23. Identify the oxidation number for manganese in MnO4-.
A. -7
B. 7
C. 8
D. 9
24. Which of the following is more difficult to reduce than the H+ ion?
A. I2
B. Ag+
C. Zn2+
D. Cu2+
25. The equation for the decomposition of nitrous acid is
3HNO2 ® 2NO + HNO3 + H2O
Which of the following is correct?
A. This is a redox reaction.
B. This is an acid-base reaction.
C. This is a reduction half equation.
D. This is an oxidation half equation.
26. An equation for the rusting of iron is shown below:
4Fe + 3O2 ® 2Fe2O3
Which of the following is false?
A. This is a redox reaction.
B. O2 is the oxidizing agent.
C. Metallic iron is reduced to Fe3+.
D. Metallic iron is the reducing agent.
27. In which of the following chemical changes will there be an oxidation number
change of +3 ?
A. Cr3+ ® Cr2+
B. ClO- ® ClO2-
C. Cr3+ ® Cr2O72-
D. Mn2+ ® MnO4-
28. Consider the following spontaneous reactions:
Cd2+ + Np ® Cd + Np3+
Cd + Pd2+ ® Pd + Cd2+
Np3+ + Ce ® Np + Ce3+
Which is the strongest oxidizing agent?
A. Cd2+
B. Ce3+
C. Np3+
D. Pd2+
29. Consider the following equation:
H3AsO4 + 4Zn + 8H+ ®AsH3 + 4Zn2+ + 4H2O
Which of the following is correct?
A. Oxygen is reduced.
B. Arsenic is reduced.
C. Zinc is the oxidizing agent.
D. The reaction is not a redox reaction.
30. What is the oxidation number of iron in magnetite, Fe3O4 ?
A. +4/3
B. +2
C. +8/3
D. +3
Consider the following Reaction: HCl(aq) + NaOH(aq) → H2O(1) + NaCl (aq) The rate of this
reaction could be determined by monitoring the change of concentration of :
A. H+
B. Cl -
C. Na +
D. H2O
2. Consider the following reaction: 2Al (s) + 6HCl (aq) → 2AlCl 3(aq) + 3H 2(g)
A 0.040 mole piece of aluminum reacted completely in 20 s. The rate of formation of hydrogen
gas is:
A. 0.0013 mol/s
B. 0.0020 mol/s
C. 0.0030 mol/s
D. 0.0060 mol/s
3. Consider the following reaction: Zn(s) + 2HCl (aq) → ZnCl 2(aq) + H 2(g)
Solid zinc was added to 1.0 M HCl. In 20.0 s. the temperature of the container increased by
0.05oC and 25.00 ml of H2 was produced. The rate of this reaction was:
A. 0.5oC
B. 1.0 M HCl/s
C. 1.25 ml H2/s
D. 0.050 mol HCl/s
4. Consider the following reaction : N 2(g) + 3H 2(g) → 2NH 3(g)
If the rate of formulation of NH3 is 9.0 x 10–4 mol/s, then the rate of consumption of N2 is:
A. 4.5 x 10-4 mol/s
B. 6.0 x 10-4 mol/s
C. 9.0 x 10-4 mol/s
D. 1.4 x 10-3 mol/s
5. In general, the reaction rates double when the temperature is increased by 10oC . The
temperature of a reaction is increased by 40oC. The rate of the reaction will be increased by:
A. 2
B. 4
C. 8
D. 16
6. Consider the following reaction: 2NO2(g) → 2NO(g) + O2(g)
Under certain conditions, the rate of decomposition of NO2 is 3.2 x 10-3 mol/s. The rate of the
formation of O2 is:
A. 1.6 x 10-3 mol/s
B. 3.2 x 10-3 mol/s
C. 4.8 x 10-3 mol/s
D. 6.4 x 10-3 mol/s
7. An 8.00 g piece of magnesium was placed into 6.0 M HCl . After 25 s. 3.50 g of unreacted
magnesium remained. The average rate at which magnesium was consumed is:
A. 0.14 g/s
B. 0.18 g/s
C. 0.32 g/s
D. 4.50 g/s
8. The rate of a chemical reaction can be expressed in
A. grams per mole.
B. Energy consumed per mole.
C. volume of gas per unit time.
D. moles formed per liter of solution
9. Consider the following reaction at a constant temperature in an open system:
MgCO3(s) + 2HCl(aq) → CO2(g) + H2O(l) + MgCl 2(aq)
Which of the following properties could be used to determine reaction rate?
A. Mass of the system
B. Pressure of the gas
C. Concentration of H2O
D. Concentration of MgCO3
10. At 30oC a 25.0 mL sample of bleach decomposes producing 50.0 mL of oxygen gas in 80
seconds. The rate of oxygen formation can be determined by the expression
A. 50.0 mL/80s
B. 50.0 mL/30oC
C. 25.0 mL/80s
D. 25.0 mL/30oC
11. A 25.0 mL sample of hydrogen peroxide decomposes producing 50.0 mL of oxygen gas in
137 s. The rate of formation of O2 in mL/min is
A. 0.182 mL/min
B. 0.365 mL/min
C. 10.9 mL/min
D. 21.9 mL/min
12. Consider the following reaction: 2N2O5(g) → 4 NO2(g) + 02(g)
At a certain temperature the rate of decomposition of N2O5 is 2.5 x 10-6 mol/s. The rate of
formation of NO2 is
A. 1.0 x 10-5 mol/s
B. 1.3 x 10-6 mol/s
C. 2.5 x 10-6 mol/s
D. 5.0 x 10-6 mol/s
13. Consider the following reaction:
2CaCrO4(s) + 2H+(aq) ® 2Ca2+(aq) + H2O(l) + Cr2O72-(aq)
(orange)
The progress of the reaction could be followed by observing the rate of
A. mass loss
B. decrease in pH
C. precipitate formation
D. formation of orange colour in the solution
14. Which of the following could be used to monitor the rate of the reaction
A. change in time
change in concentration
B. change in mass
change in concentration
C. change in concentration
change in time
D. change in concentration
change in mass
15. Consider the following reaction:
N2H4(l) + 2H2O2(l) ® N2(g) + 4H20(l)
In 1.0 seconds, 0.015 g of H2O2 is consumed. The rate of production of N2 is
A. 6.2 x 10-3 g/s
B. 7.5 x 10-3 g/s
C. 3.1 x 10-4 g/s
D. 1.5 x 10-2 g/s
16. Which of the following could be used to measure the rate of the reaction?
A. mL/s
B. mL/g
C. g/mL
D. mL/mol
17. Consider the following reaction in an open container:
MgCO3(s) + 2HCl(aq) ® MgCl2(aq) + H2O(l) + CO2(g)
The rate of this reaction could be calculated by using which of the following?
A. a change in Cl-
B. an increase in [HCl]
C. a change in pressure
D. a decrease in mass of the system
18. Consider the following reaction in an closed container:
MgCO3(s) + 2HCl(aq) ® MgCl2(aq) + H2O(l) + CO2(g)
The rate of this reaction could be calculated by using which of the following?
A. a change in Cl-
B. an increase in [HCl]
C. a change in pressure
D. a decrease in mass of the system
19. Consider the following reaction in an open beaker:
MgCO3(s) + 2HCl(aq) ® MgCl2(aq) + H2O(l) + CO2(g)
The rate of this reaction could be calculated by using which of the following?
A. an increase in MgCO3 mass
B. a decrease in [MgCO3]
C. an increase in [H2O]
D. mass of the system over time
20. Consider the following reaction:
MgCO3(s) + 2HCl(aq) ® MgCl2(aq) + H2O(l) + CO2(g)
If the rate of consumption of HCl is 2.0 g/min what is the rate of formation of CO2?
A. 1.2 g/min
B. 2.4 g/min
C. 1.0 g/min
D. 2.0 g/min
21. Which of the following could not be used to measure the rate of the reaction?
A. s-1
B. mL/s
C. M/hour
D. mol/L
22. Consider the following reaction:
Fe2O3(s) + 2Al(s) ® Al2O3(s) + 2Fe(s)
If 0.50 mol of Fe is produced in 10.0 sec, what is the rate of consumption of Fe2O3 in
mol/s?
A. 5.0 x 10-2 mol/s
B. 2.5 x 10-2 mol/s
C. 1.0 x 10-1 mol/s
D. 5.0 mol/s
Which of the following reactions is the slowest at room temperature?
A. Zn(s) + S(s) → ZnS(s)
B. Ba2+(aq) + SO42-(aq) → BaSO4(s)
C. NH3(g) + HCl(g) → NH4Cl(g)
D. 2 Ag+(aq) + CO32-(aq) → Ag2CO3(s)
2. Dust particles suspended in the air inside unheated grain elevators can sometimes react
explosively because the dust particles have a:
A. High kinetic energy
B. High activation energy
C. Catalytic effect on the reaction
D. Large surface area for the reaction
3. Consider the following reaction: 2H2O2(aq) → 2 H2O(t) + O2(g)
When 1.0 g of KI is added to the H2O2, bubbles of O2 are produced at an increased rate.
When the reaction is complete, the mass of KI is 1.0 g. The KI is a
A. Product
B. Catalyst
C. Reactant
D. Reaction Intermediate
4. Consider the following factors:
I. Concentration of reactants.
II. Temperature of reactants.
III. Surface area of reactants.
The factors that affect the rate of a chemical reaction between two gases are
A. I and II only
B. I and III only
C. II and III only.
D. I, II, and III
5. Consider the following reactions:
I. N2(g) + O2(g) → 2NO(g)
II. 2Mg(s) + O2(g) → 2MgO(s)
III. CaCO3(s) + 2H+(aq) → Ca2+(aq) + H2O(l) + CO2(g)
Increasing the surface area will increase the reaction rate in
A. II only
B. I and III only
C. II and III only
D. I, II and III
6. An untreated sugar cube does not burn when held over a lighted match. A sugar cube
coated with cigarette ash readily ignites and burns. All of the cigarette ash remains after
the reaction. The factor that caused this change in rate is the
A. Nature of reactants
B. Presence of a catalyst
C. Increase in surface area
D. Increase in concentration
7. Which combination of factors will affect the rate of the following reaction?
Zn(s) + 2HCl (aq) → ZnCl2(aq) + H2(g)
A. Temperature and surfaces only
B. Temperature and concentration only
C. Concentration and surface area only
D. Temperature, concentration, and surface area
8. The addition of a catalyst to a reaction provides an alternative mechanism with
A. Lower activation energy and lower reaction rate
B. Lower activation energy and higher reaction rate
C. Higher activation energy and lower reaction rate
D. Higher activation energy and higher reaction rate
9. Consider the following reaction:
2MnO4-(aq) + 5C2O42-(aq) + 16H+(aq) ® 2Mn2+(aq) + 10CO2(g) + 8H2O(l)
The rate of decomposition of the oxalate ion is increased by
A. Adding NaOH
B. Removing CO2
C. Adding a catalyst
D. Decreasing the pressure.
10. Which of the following factors affect the rates of both homogeneous and heterogeneous
reactions
I. Nature of reactants
II. Presence of a catalyst
III. Temperature of system
IV Concentration of reactants
A. I and IV only
B. II and III only.
C. II, III and IV only
D. I, II, III and IV
11. Which of the following factors affects the rate of heterogeneous reactions only.
A. Nature of reactants
B. Temperature of system
C. Surface area of reactants
D. Concentration of reactants
12. Consider the following reaction: 2S(s) + 302(g) → 2SO3(g) + heat
The rate of this reaction could be increased by
A. Decreasing temperature
B. Adding a catalyst
C. Increasing the concentration of S(s)
D. Increasing the concentration of SO3(g)
13. 6.0 g of Mg reacts with some HCl in two different experiments. The reaction for both
was:
Mg(s) + 2HCl(aq) ® MgCl2(aq) + H2(g)
In the first experiment, it took 6.2 minutes for all the Mg to react. In the second
experiment, it took 10.8 minutes for all the Mg to react. Which of the following could
explain the change in rate in the second experiment?
A. A catalyst was added
B. The Mg was powdered
C. The H2 was decreased
D. The temperature was decreased
14. Which of the following reactions is most likely to proceed at the greatest rate?
A. Zn(s) + S(s) ® ZnS(s)
B. H2(g) + I2(s) ® 2HI(g)
C. Cu(s) + Cl2(g) ® CuCl2(s)
D. 2KOH(aq) + H2SO4(aq) ® 2H2O(l) + K2SO4(aq)
15. Consider the following reaction:
Mg(s) + 2HCl(aq) ® MgCl2(aq) + H2(g)
Which of the following would increase the reaction rate?
A. an increase in pressure
B. an increase in temperature
C. an increase in the concentration of H2
D. an increase in the concentration of MgCl2
16. When a candle C20H42 burns, the following reaction occurs:
2C20H42(s) + 61O2(g) ® 40CO2 + 42H2O(g)
If the rate of production of CO2 is 0.49 g/min, what is the rate of oxygen consumption?
A. 0.24 g/min
B. 0.27 g/min
C. 0.36 g/min
D. 0.54 g/min
17. Which of the following properties could best be monitored in order to determine the
reaction rate of the above burning candle?
A. mass of C20H42
B. pressure of H2O
C. surface area of C20H42
D. concentration of C20H42
18. Which of the following factors only affects the rate of heterogeneous reactions?
A. nature of reactants
B. presence of a catalyst
C. temperature of reactants
D. surface area of reactants
19. Consider the following experimental results:
Experiment 1 Experiment 2
Reactants Ca(s) + HCl(aq) Zn(s) + HCl(aq)
Temperature 20 0C 40 0C
Concentration 1.0 M 2.0 M
Rates Fast Slow
Which factor would account for the faster reaction rate in Experiment 1?
A. temperature
B. surface area
C. nature of reactants
D. solution concentration
20. Consider the following reaction:
2NO(g) + O2(g) ® 2NO2(g)
How could the rate of this reaction be increased?
A. Reduce the pressure
B. Increase the volume
C. Remove some NO2(g)
D. Increase the temperature
21. Which factor explains why coal dust is explosive?
A. temperature
B. surface area
C. concentration
D. addition of catalyst
22. Which factor explains why potassium generally reacts faster than magnesium?
A. surface area
B. temperature
C. concentration
D. nature of reactants
23. Which factor explains why gasoline vapour is explosive?
A. temperature
B. surface area
C. concentration
D. nature of the reactant
Which of the following are necessary for successful collisions to occur?
I Favorable collision geometry
II Sufficient Kinetic energy
III Large ∆H
A. I only
B. I and II only
C. II and III only
D. I, II, and III
2. Collision theory states that
A. All collisions lead to chemical reactions
B. Most collisions lead to chemical reactions
C. Very few reactions involve particle collisions
D. Effective collisions lead to chemical reactions
3. A catalyst increases the rate of a reaction by
A. Increasing the concentration of the reactant(s)
B. Decreasing the concentration of the reactant(s)
C. Increasing the activation energy of the overall reaction
D. Decreasing the activation energy of the overall reaction
4. Milk is refrigerated in order to slow the rate of decomposition by bacterial action. The
decrease in reaction rate is due to
A. A decrease in surface area
B. A decrease in ∆H for the reaction
C. A decrease in the fraction of particles possessing sufficient energy
D. The introduction of an alternate pathway with greater activation energy
5. In general, a chemical reaction requiring a large activation energy will proceed
A. At a fast rate
B. At a slow rate
C. Only at a low temperature
D. Only at low concentrations
6. Consider the following reaction:
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
As the temperature of the above system is increased, the number of collisions
A. Increases but fewer are effective
B. Decreases and fewer are effective
C. Increases and more are effective
D. Decreases but more are effective
7. The minimum amount of energy needed to start a reaction is called the
A. Activation energy
B. Energy of a reaction
C. Entropy of a reaction.
D. Reaction mechanism energy
8. When a lit match is touched to the wick of a candle, the candle begins to burn. When the
match is removed, the candle continues to burn. In this reaction, the match
A. Behaves as a catalyst
B. Supplies activation energy
C. Is part of the rate-determining step
D. Lowers the activation energy barrier
9. Consider the following collisions, each one occurring at the same temperature
Before Collision Collision After Collision
Which one of the following factors explains why collision one is successful while
collision two is not successful?
A. Catalyst
B. Geometry
C. Concentration
D. Kinetic energy
10. Consider the following factors
I Reactant particles collide
II Sufficient kinetic energy is present
III A favorable geometry exists
IV Catalysts are present
Which combination of the above factors is required for successful collisions
A. I only
B. II and III only
C. I, II, and III only
D. I, II, III, and IV
11. To increase the rate of a reaction, there must be
A. Decrease in the frequency of collisions
B. An Increase in the frequency of collisions.
C. A decrease in the frequency of successful collisions
D. An increase in the frequency of successful collisions
12. For collisions to be successful, reactants must have
A. Favorable geometry only
B. Sufficient heat of reaction only
C. Sufficient potential energy only
D. Sufficient kinetic energy and favorable geometry
13. A reactant surface area is increased. There are:
A. more collisions and greater collision energy
B. More collisions but the same collision energy
C. the same number of collisions and greater collision energy
D. the same number of collisions but the same collision energy
14. Which of the following would change the value of the activation energy for a
heterogeneous reaction?
A. adding a catalyst
B. changing the surface area
C. changing the reactant concentration
D. changing the average kinetic energy
15. Which of the following would change the value of the activation energy for a
heterogeneous reaction?
A. adding an inhibitor
B. changing the surface area
C. changing the temperature
D. changing the average kinetic energy
16. What happens to the activation energy as the temperature in a reacting system decreases?
A. the activation energy increases
B. the activation energy decreases
C. the activation energy stays the same
D. the activation energy is converted to kinetic energy
17. How does the addition of a catalyst increase the reaction rate of an endothermic reaction?
A. It reduces the ΔH of the reaction.
B. It increases the ΔH of the reaction.
C. It reduces the required activation energy.
D. It causes the reaction to become exothermic.
18. Which of the following would result in a successful collision between reactant particles?
A. particles have sufficient KE
B. particles convert their entire PE into KE
C. particles are in an excited state and are catalyzed
D. particles have sufficient KE and good molecular orientation
19. A spark causes propane gas to explode. According to the collision theory, the spark:
A. lowered the Ea
B. increased the Ea
C. provided the Ea
D. acted as a catalyst
20. Consider the following reaction:
2H2O2(aq) → O2 + 2H2O(l)
A small amount of KI is added and the reaction rate increases. The best explanation is
that KI:
A. is a catalyst
B. causes more collisions
C. causes harder collisions
D. increases the temperature
21. The reaction temperature is increased. There are:
A. more collisions and greater collision energy
B. more collisions but the same collision energy
C. the same number of collisions and greater collision energy
D. the same number of collisions but the same collision energy
22. A reactant concentration is increased. There are:
A. more collisions and greater collision energy
B. more collisions but the same collision energy
C. the same number of collisions and greater collision energy
D. the same number of collisions but the same collision energy
23. A reactant surface area is increased. There are:
A. more collisions and greater collision energy
B. more collisions but the same collision energy
C. the same number of collisions and greater collision energy
D. the same number of collisions but the same collision energy
24. In a chemical reaction, which of the following is not true?
A. most collisions are successful
B. successful collisions have favourable geometry
C. successful collisions have sufficient energy
D. a collision is required
25. Which of the following increases the fraction of successful collisions:
I. Increasing temperature
II. Increase in Surface Area
III. Adding a Catalyst
IV. Increase in Reactant Concentration
A. I and III only
B. I and IV only
C. II and III
D. I, II, III, and IV
The addition of a catalyst to a reaction provides an alternative mechanism with
A. Lower activation energy and lower reaction rate
B. Lower activation energy and higher reaction rate
C. Higher activation energy and lower reaction rate
D. Higher activation energy and higher reaction rate
2. Consider the following Reaction: ½ N2(g) + ½ O2(g) → NO(g)
∆H = +90 kJ/mol NO
The correct equation including the heat term is
A. N2(g) + O2(g) +90 kJ ------- > 2NO(g)
B. N2(g) + O2(g) +180 kJ ------- > 2NO(g)
C. N2(g) + O2(g) ------- > 2NO(g) +90kJ
D. N2(g) + O2(g) ------- > 2NO(g) +180kJ
3. A forward reaction has an activation energy of 50 kJ and a ∆H of –100 kJ.
The PE diagram, which describes this reaction, is
4. Consider the following potential energy diagram
The Activation energy for the forward reaction is
A. 25 kJ
B. 50 kJ
C. 75 kJ
D. 125 kJ
5. Consider the following reaction: ½ H2(g) + ½ I2(g) ------- > HI(g)
The activation energy for the formation of HI is 167 kJ and for the decomposition of HI
is 139 kJ. The reaction for the formation of HI is
A. Exothermic and the ∆H = -28 kJ
B. Exothermic and the ∆H = +28 kJ
C. Endothermic and the ∆H = -28 kJ
D. Endothermic and the ∆H = +28 kJ
6. Consider the following potential energy diagram
The energy interval the represents the activation energy for the reverse reaction is
A. I
B. II
C. III
D. IV
7. As reactant molecules approach each other
A. Heat is released
B. A reaction intermediate forms
C. Kinetic energy changes to potential energy
D. Potential energy changes to kinetic
8. Which of the following equations represents an endothermic reaction?
A. N204(g) + 59 kJ ------- > 2NO2(g)
B. 2H2(g) + 02(g) ------- > 2H2O(l) + 572 kJ
C. 2BrCl(g) – 29.3 kJ ------ > Br2(g) + Cl2(g)
D. C(s) + O2(g) ------- > CO2(g) ∆H = -394 kJ
9. Consider the following potential energy diagram
The interval representing ∆H for the reverse reaction is
A. 1
B. 2
C. 3
D. 4
10. Which of the following corresponds to the fastest reaction at room temperature
11. When a catalyst is added to a reaction, ∆H will
A. Increase slowly
B. Remain constant
C. Decrease slowly
D. Increase rapidly due to alternate pathway
12. Consider the following potential energy diagram that represents two different reactions.
Which of the following statements is correct?
A B
A. Reactions A and B are both exothermic
B. Reactions A and B are both endothermic
C. Reaction A is exothermic and reaction B is endothermic
D. Reaction A in endothermic and reaction B is exothermic
13. Consider the following reaction: ½ H2(g) + ½ I2(g) ------- > HI(g) ∆H = +28 kJ
The activation energy for the formation of HI is 167 kJ. the activation energy for the
decomposition of HI is:
A. 28 kJ
B. 139 kJ
C. 167 kJ
D. 195 kJ
14. Consider the following potential energy diagram for
14 to 16
Which of the following are the values for the activation energy Ea and change in
enthalpy ΔH for the forward reaction?
Ea(kJ) ΔH(kJ)
A. 300 –50
B. 150 +50
C. 100 –50
D. 100 +50
15. Which of the following are the values for the activation energy Ea and change in enthalpy
ΔH for the reverse reaction?
Ea (kJ) ΔH (kJ)
A. 300 –50
B. 150 +50
C. 100 –50
D. 100 +50
16. What is the PE of the reactants and activated complex?
Reactants (kJ) Activated Complex (kJ)
A. 50 50
B. 300 150
C. 200 200
D. 150 300
17. Which of the following would have a positive value for ΔH?
I. the evaporation of alcohol
II. the burning of a candle
III. an explosive reaction
IV. a chemical cold pack
A. III only
B. IV only
C. I and IV
D. II and III
18. Which of the following represents the value for the activation energy of the
forward reaction in an equilibrium system?
A. Ea forward = Ea reverse + ΔH
B. Ea forward = Ea reverse - ΔH
C. Ea forward = ΔH - Ea reverse
D. Ea forward = ΔH - Ea forward
19. Consider the following reaction: H2(g) + Cl2(g) → 2HCl(g)
As a molecule of H2 approaches a molecule of Cl2 on a collision course, how do the KE
and PE change?
KE PE
A. increases decreases
B. decreases increases
C. decreases decreases
D. increases increases
20. Consider the following reaction: H2(g) + Cl2(g) → 2HCl(g)
As the activated complex forms changes to HCl
KE PE
A. increases decreases
B. decreases increases
C. decreases decreases
D. increases increases
21. The activated complex is best described as:
A. stable maximum PE minimum KE
B. stable minimum PE maximum KE
C. unstable maximum PE minimum KE
D. unstable minimum PE maximum KE
22. In a certain reaction ΔH = -136 kJ and Ea reverse = 236 kJ. Which of the following is
true of its forward reaction?
A. The reaction is exothermic and Ea = -100 kJ.
B. The reaction is exothermic and Ea = 100 kJ.
C. The reaction is endothermic and Ea = 372 kJ.
D. The reaction is endothermic and Ea = 232 kJ
23. In a certain reaction ΔH = -136 kJ and Ea = 96 kJ. Which of the following is true about
the reverse reaction?
A. The reverse reaction is exothermic and Ea = -40 kJ.
B. The reverse reaction is exothermic and Ea = 40 kJ.
C. The reverse reaction is endothermic and Ea = 96 kJ.
D. The reverse reaction is endothermic and Ea = 232kJ
24. Consider the following information for a reversible chemical reaction:
Forward activation energy 20 kJ Reverse activation energy 30 kJ
Which of the following describes the reaction type and enthalpy change for the
forward reaction?
Reaction Type ΔH Value
A. exothermic 10 kJ
B. exothermic -10 kJ
C. endothermic 10 kJ
D. endothermic -10 kJ
25. Consider the following information for a reversible chemical reaction:
Forward activation energy 20 kJ Reverse activation energy 30 kJ
Which of the following describes the reaction type and enthalpy change for the reverse
reaction?
Reaction Type ΔH Value
A. exothermic 10 kJ
B. exothermic -10 kJ
C. endothermic 10 kJ
D. endothermic -10 kJ
26.
Which of the following is true for the forward reaction?
Reaction PE of Activated Complex (kJ) ΔH (kJ)
A. catalyzed 100 -50
B. uncatalyzed 300 -50
C. catalyzed 250 +50
D. uncatalyzed 150 -50
27. An activated complex can be described as
A. a particle of maximum KE and minimum PE.
B. a stable particle found in a reaction mechanism.
C. an unstable particle that is neither reactant nor product.
D. a particle which is first used then regenerated in a reaction mechanism.
28. Which of the following describes the Ea of a fast reaction and the stability of its
activated complex?
Ea Activated Complex
A. small unstable
B. small stable
C. large unstable
D. large stable
29. As an activated complex changes into products, what changes occur in the chemical
bonds of the activated complex and the PE of the system?
Bonds PE
A. form increases
B. form decreases
C. break increases
D. break decreases
30. As reactants change into an activated complex, what changes occur in the chemical bonds
of the activated complex and the PE of the system?
Bonds PE
A. form increases
B. form decreases
C. break increases
D. break decreases
Use this diagram for 31 -33
31. Which of the following describes the reverse reaction?
Activation Energy (kJ) ∆H (kJ)
A. uncatalyzed 200 −100
B. catalyzed 200 −100
C. uncatalyzed 300 +100
D. catalyzed 300 +100
32. Consider the following reaction:
CH4 + Cl2 → CH2Cl2 + H2
Which answer best describes the activated complex?
Formula KE relative to reactants
A. CH4 higher
B. CH4 lower
C. CH4Cl2 higher
D. CH4Cl2 lower
Consider the following reaction mechanism
Step 1: M + X → MX
Step 2: MX + A → D + X
The chemical species MX is a(n)
A. Catalyst
B. Inhibitor
C. Final Product
D. Reaction Intermediate
2. Consider the following reaction mechanism
Step 1: NO2 + NO2 → NO + NO3
Step 2: NO3 + CO → NO2 + CO2
The overall reaction is
A. 2NO2 → NO3 + NO
B. NO2 + CO → NO + CO2
C. NO3 + CO → NO2 + CO2
D. NO2 + NO3 + CO → NO3 + NO2 + NO + CO2
3. Consider the following reaction mechanism
Step 1: V3+ + Cu2+ → V4+ + Cu+ (slow)
Step 2: Cu+ + Fe3+ → Cu2+ + Fe2+ (fast)
The reaction intermediate is
A. Cu+
B. Cu2+
C. V3+
D. Fe3+
4. Consider the following reaction Mechanism
Step 1: H2O2 + I - → H2O + IO-
Step 2: H2O2 + IO - → H2O + O2 + I -
The reaction intermediate is
A. I-
B. IO -
C. H2O
D. H2O2
5. Consider the following potential energy diagram
The above potential energy diagram represents an
A. Exothermic reaction involving one step
B. Exothermic reaction involving two steps
C. Endothermic reaction involving one step
D. Endothermic reaction involving two steps
6. Consider the following reaction mechanism
Step 1: NO2(g) + NO2(g) → NO(g) + NO3(g) (slow)
Step 2: NO3(g) + CO(g) → CO2(g) + NO2(g) (fast)
Which one of the following changes would result in the greatest increase in reaction rate
A. Increase [CO]
B. Decrease [NO]
C. Increase [NO2]
D. Increase [NO3]
7. An uncatalyzed reaction was found to produce 40 kJ of energy in 10 mins. When catalyzed,
the same reaction produced 40 kJ of energy in 2 mins. Which one of the following potential
energy diagrams is consistent with the above data?
8. Consider the following reaction mechanism
Step 1: ICl + H2 → HI + HCl (slow)
Step 2: ICl + HI → HCl + I2 (fast)
The Species HCl is a
A. Product
B. Catalyst
C. Reactant
D. Reaction Intermediate
9. Consider the following reaction mechanism
Step 1: Cl(g) + O3(g) → ClO(g) + O2(g)
Step 2: O(g) + ClO(g) → Cl(g) + O2(g)
The Reaction intermediate is
A. Cl
B. O2
C. O3
D. ClO
10. In a reaction mechanism, the rate determining step is the
A. Fastest and has the lowest reaction rate.
B. Fastest and has the highest activation energy
C. Slowest and has the lowest activation energy
D. Slowest and has the highest activation energy
11. Select the true statement concerning the above potential energy diagram.
A. The catalyzed reaction has a larger ∆H
B. The uncatalyzed reaction has a larger ∆H
C. The catalyzed reaction has a greater rate of reaction
D. The uncatalyzed reaction has a greater rate of reaction
12. Which point on the diagram above represents the potential energy of the activated complex
formed in the uncatalyzed reaction?
A. I
B. II
C. III
D. IV
13. Consider the following reaction
Step 1: NO(g) + O3(g) ------ > NO2(g) + O2(g)
Step 2: O(g) + NO2(g) ------ > NO(g) + O2(g)
The catalyst is
A. O2
B. O3
C. NO
D. NO2
14. Consider the following reaction mechanism
Step 1: N2O(g) ------ > N2(g) + O(g)
Step 2: N2O(g) + O(g) ------ > N2(g) + O2(g)
The reactant in the overall reaction is
A. O
B. O2
C. N2
D. N2O
15. Consider the following reaction
O3(g) + NO(g) ----- > NO2(g) + O2(g)
NO2(g) + O(g) ------ > NO(g) + O2(g)
The product in the overall reaction is
A. O2
B. O3
C. NO
D. NO2
Use the following reaction mechanism to answer questions 16 and 17.
Step 1: 2PO → P2O2 (fast)
Step 2: P2O2 + H2 → P2O + H2O (slow)
Step 3: P2O + H2 → P2 + H2O (fast)
16. Increasing the concentration of which of the following substances would cause the
greatest increase in the reaction rate?
A. H2
B. PO
C. P2O
D. H2O
17. Which of the following are products in the overall reaction?
I P2
II P2O2
III PO2
IV H2O
A. I and II only
B. I and IV only
C. II and III only
D. III and IV only
18. The Intermediates are:
A. NO H2
B. H2O P2
C. P2O2 PO
D. P2O2 P2O
19. Which of the following could describe a catalyst?
A. A substance that increases the reaction time.
B. A substance that provides an alternate mechanism with higher activation energy.
C. A substance that is formed in one step and used up in a subsequent step in a
reaction mechanism.
D. A substance that is used up in one step and reformed in a subsequent step in
a reaction mechanism.
20. Consider the following reaction: 2PO(g) + O2(g) → 2PO2(g)
Why would this reaction probably involve more than one step?
A. There is insufficient activation energy.
B. This reaction has high activation energy.
C. Reactions between gases are typically slow.
D. A successful collision between three molecules is unlikely.
21. Consider the following reaction mechanism:
Step 1 Cl3 → Cl2 + Cl
Step 2 Cl3 + Cl → 2Cl2
Which of the following could represent the activated complex for Step 2?
A. Cl
B. Cl2
C. Cl3
D. Cl4
22. Consider the reaction: 2C4H10(g) + 13O2(g) → 8CO2(g) + 10H2O(l)
Which of the following explains, in terms of collision theory, why this reaction occurs in
more than one step?
A. a low C4H12(g) pressure
B. low temperature of reactant mixture
C. low probability of a multi-particle collision
D. particles collide with insufficient kinetic energy
23. Consider the following reaction mechanism and overall reaction:
Step 1 ½ O2(g) + NO(g) → NO2(g)
sunlight
Step 2 NO2(g) → NO(g) + O(g)
Step 3 O2(g) + O(g) → O3(g)
Overall 3/2 O2 (g) → O3(g)
What is the catalyst in this mechanism?
A. O
B. NO
C. NO2
D. sunlight
24. What is an intermediate in this mechanism?
A. O
B. NO
C. O3
D. sunlight
25. Consider the following reaction mechanism:
Step 1 NOI → NO + I
Step 2 NOI + I → NOI2
Identify the reaction intermediate.
A. I
B. NOI2
C. NO
D. NOI
26. Consider the following reaction mechanism:
Step 1 2NO2 → NO3 + NO
Step 2 NO3 + CO → NO2 + CO2
Identify a product in the overall reaction.
A. CO
B. CO2
C. NO2
D. NO3
27. Consider the following reaction mechanism:
Step 1 2NO2 → NO3 + NO
Step 2 NO3 + CO → NO2 + CO2
Identify an intermediate.
A. CO
B. CO2
C. NO2
D. NO3
Which of the following are necessary for successful collisions to occur?
I Favorable collision geometry
II Sufficient Kinetic energy
III Large ∆H
A. I only
B. I and II only
C. II and III only
D. I, II, and III
2. Collision theory states that
A. All collisions lead to chemical reactions
B. Most collisions lead to chemical reactions
C. Very few reactions involve particle collisions
D. Effective collisions lead to chemical reactions
3. A catalyst increases the rate of a reaction by
A. Increasing the concentration of the reactant(s)
B. Decreasing the concentration of the reactant(s)
C. Increasing the activation energy of the overall reaction
D. Decreasing the activation energy of the overall reaction
4. Milk is refrigerated in order to slow the rate of decomposition by bacterial action. The
decrease in reaction rate is due to
A. A decrease in surface area
B. A decrease in ∆H for the reaction
C. A decrease in the fraction of particles possessing sufficient energy
D. The introduction of an alternate pathway with greater activation energy
5. In general, a chemical reaction requiring a large activation energy will proceed
A. At a fast rate
B. At a slow rate
C. Only at a low temperature
D. Only at low concentrations
6. Consider the following reaction:
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
As the temperature of the above system is increased, the number of collisions
A. Increases but fewer are effective
B. Decreases and fewer are effective
C. Increases and more are effective
D. Decreases but more are effective
7. The minimum amount of energy needed to start a reaction is called the
A. Activation energy
B. Energy of a reaction
C. Entropy of a reaction.
D. Reaction mechanism energy
8. When a lit match is touched to the wick of a candle, the candle begins to burn. When the
match is removed, the candle continues to burn. In this reaction, the match
A. Behaves as a catalyst
B. Supplies activation energy
C. Is part of the rate-determining step
D. Lowers the activation energy barrier
9. Consider the following collisions, each one occurring at the same temperature
Before Collision Collision After Collision
Which one of the following factors explains why collision one is successful while
collision two is not successful?
A. Catalyst
B. Geometry
C. Concentration
D. Kinetic energy
10. Consider the following factors
I Reactant particles collide
II Sufficient kinetic energy is present
III A favorable geometry exists
IV Catalysts are present
Which combination of the above factors is required for successful collisions
A. I only
B. II and III only
C. I, II, and III only
D. I, II, III, and IV
11. To increase the rate of a reaction, there must be
A. Decrease in the frequency of collisions
B. An Increase in the frequency of collisions.
C. A decrease in the frequency of successful collisions
D. An increase in the frequency of successful collisions
12. For collisions to be successful, reactants must have
A. Favorable geometry only
B. Sufficient heat of reaction only
C. Sufficient potential energy only
D. Sufficient kinetic energy and favorable geometry
13. A reactant surface area is increased. There are:
A. more collisions and greater collision energy
B. More collisions but the same collision energy
C. the same number of collisions and greater collision energy
D. the same number of collisions but the same collision energy
14. Which of the following would change the value of the activation energy for a
heterogeneous reaction?
A. adding a catalyst
B. changing the surface area
C. changing the reactant concentration
D. changing the average kinetic energy
15. Which of the following would change the value of the activation energy for a
heterogeneous reaction?
A. adding an inhibitor
B. changing the surface area
C. changing the temperature
D. changing the average kinetic energy
16. What happens to the activation energy as the temperature in a reacting system decreases?
A. the activation energy increases
B. the activation energy decreases
C. the activation energy stays the same
D. the activation energy is converted to kinetic energy
17. How does the addition of a catalyst increase the reaction rate of an endothermic reaction?
A. It reduces the ΔH of the reaction.
B. It increases the ΔH of the reaction.
C. It reduces the required activation energy.
D. It causes the reaction to become exothermic.
18. Which of the following would result in a successful collision between reactant particles?
A. particles have sufficient KE
B. particles convert their entire PE into KE
C. particles are in an excited state and are catalyzed
D. particles have sufficient KE and good molecular orientation
19. A spark causes propane gas to explode. According to the collision theory, the spark:
A. lowered the Ea
B. increased the Ea
C. provided the Ea
D. acted as a catalyst
20. Consider the following reaction:
2H2O2(aq) → O2 + 2H2O(l)
A small amount of KI is added and the reaction rate increases. The best explanation is
that KI:
A. is a catalyst
B. causes more collisions
C. causes harder collisions
D. increases the temperature
21. The reaction temperature is increased. There are:
A. more collisions and greater collision energy
B. more collisions but the same collision energy
C. the same number of collisions and greater collision energy
D. the same number of collisions but the same collision energy
22. A reactant concentration is increased. There are:
A. more collisions and greater collision energy
B. more collisions but the same collision energy
C. the same number of collisions and greater collision energy
D. the same number of collisions but the same collision energy
23. A reactant surface area is increased. There are:
A. more collisions and greater collision energy
B. more collisions but the same collision energy
C. the same number of collisions and greater collision energy
D. the same number of collisions but the same collision energy
24. In a chemical reaction, which of the following is not true?
A. most collisions are successful
B. successful collisions have favourable geometry
C. successful collisions have sufficient energy
D. a collision is required
25. Which of the following increases the fraction of successful collisions:
I. Increasing temperature
II. Increase in Surface Area
III. Adding a Catalyst
IV. Increase in Reactant Concentration
A. I and III only
B. I and IV only
C. II and III
D. I, II, III, and IV
The addition of a catalyst to a reaction provides an alternative mechanism with
A. Lower activation energy and lower reaction rate
B. Lower activation energy and higher reaction rate
C. Higher activation energy and lower reaction rate
D. Higher activation energy and higher reaction rate
2. Consider the following Reaction: ½ N2(g) + ½ O2(g) → NO(g)
∆H = +90 kJ/mol NO
The correct equation including the heat term is
A. N2(g) + O2(g) +90 kJ ------- > 2NO(g)
B. N2(g) + O2(g) +180 kJ ------- > 2NO(g)
C. N2(g) + O2(g) ------- > 2NO(g) +90kJ
D. N2(g) + O2(g) ------- > 2NO(g) +180kJ
3. A forward reaction has an activation energy of 50 kJ and a ∆H of –100 kJ.
The PE diagram, which describes this reaction, is
4. Consider the following potential energy diagram
The Activation energy for the forward reaction is
A. 25 kJ
B. 50 kJ
C. 75 kJ
D. 125 kJ
5. Consider the following reaction: ½ H2(g) + ½ I2(g) ------- > HI(g)
The activation energy for the formation of HI is 167 kJ and for the decomposition of HI
is 139 kJ. The reaction for the formation of HI is
A. Exothermic and the ∆H = -28 kJ
B. Exothermic and the ∆H = +28 kJ
C. Endothermic and the ∆H = -28 kJ
D. Endothermic and the ∆H = +28 kJ
6. Consider the following potential energy diagram
The energy interval the represents the activation energy for the reverse reaction is
A. I
B. II
C. III
D. IV
7. As reactant molecules approach each other
A. Heat is released
B. A reaction intermediate forms
C. Kinetic energy changes to potential energy
D. Potential energy changes to kinetic
8. Which of the following equations represents an endothermic reaction?
A. N204(g) + 59 kJ ------- > 2NO2(g)
B. 2H2(g) + 02(g) ------- > 2H2O(l) + 572 kJ
C. 2BrCl(g) – 29.3 kJ ------ > Br2(g) + Cl2(g)
D. C(s) + O2(g) ------- > CO2(g) ∆H = -394 kJ
9. Consider the following potential energy diagram
The interval representing ∆H for the reverse reaction is
A. 1
B. 2
C. 3
D. 4
10. Which of the following corresponds to the fastest reaction at room temperature
11. When a catalyst is added to a reaction, ∆H will
A. Increase slowly
B. Remain constant
C. Decrease slowly
D. Increase rapidly due to alternate pathway
12. Consider the following potential energy diagram that represents two different reactions.
Which of the following statements is correct?
A B
A. Reactions A and B are both exothermic
B. Reactions A and B are both endothermic
C. Reaction A is exothermic and reaction B is endothermic
D. Reaction A in endothermic and reaction B is exothermic
13. Consider the following reaction: ½ H2(g) + ½ I2(g) ------- > HI(g) ∆H = +28 kJ
The activation energy for the formation of HI is 167 kJ. the activation energy for the
decomposition of HI is:
A. 28 kJ
B. 139 kJ
C. 167 kJ
D. 195 kJ
14. Consider the following potential energy diagram for
14 to 16
Which of the following are the values for the activation energy Ea and change in
enthalpy ΔH for the forward reaction?
Ea(kJ) ΔH(kJ)
A. 300 –50
B. 150 +50
C. 100 –50
D. 100 +50
15. Which of the following are the values for the activation energy Ea and change in enthalpy
ΔH for the reverse reaction?
Ea (kJ) ΔH (kJ)
A. 300 –50
B. 150 +50
C. 100 –50
D. 100 +50
16. What is the PE of the reactants and activated complex?
Reactants (kJ) Activated Complex (kJ)
A. 50 50
B. 300 150
C. 200 200
D. 150 300
17. Which of the following would have a positive value for ΔH?
I. the evaporation of alcohol
II. the burning of a candle
III. an explosive reaction
IV. a chemical cold pack
A. III only
B. IV only
C. I and IV
D. II and III
18. Which of the following represents the value for the activation energy of the
forward reaction in an equilibrium system?
A. Ea forward = Ea reverse + ΔH
B. Ea forward = Ea reverse - ΔH
C. Ea forward = ΔH - Ea reverse
D. Ea forward = ΔH - Ea forward
19. Consider the following reaction: H2(g) + Cl2(g) → 2HCl(g)
As a molecule of H2 approaches a molecule of Cl2 on a collision course, how do the KE
and PE change?
KE PE
A. increases decreases
B. decreases increases
C. decreases decreases
D. increases increases
20. Consider the following reaction: H2(g) + Cl2(g) → 2HCl(g)
As the activated complex forms changes to HCl
KE PE
A. increases decreases
B. decreases increases
C. decreases decreases
D. increases increases
21. The activated complex is best described as:
A. stable maximum PE minimum KE
B. stable minimum PE maximum KE
C. unstable maximum PE minimum KE
D. unstable minimum PE maximum KE
22. In a certain reaction ΔH = -136 kJ and Ea reverse = 236 kJ. Which of the following is
true of its forward reaction?
A. The reaction is exothermic and Ea = -100 kJ.
B. The reaction is exothermic and Ea = 100 kJ.
C. The reaction is endothermic and Ea = 372 kJ.
D. The reaction is endothermic and Ea = 232 kJ
23. In a certain reaction ΔH = -136 kJ and Ea = 96 kJ. Which of the following is true about
the reverse reaction?
A. The reverse reaction is exothermic and Ea = -40 kJ.
B. The reverse reaction is exothermic and Ea = 40 kJ.
C. The reverse reaction is endothermic and Ea = 96 kJ.
D. The reverse reaction is endothermic and Ea = 232kJ
24. Consider the following information for a reversible chemical reaction:
Forward activation energy 20 kJ Reverse activation energy 30 kJ
Which of the following describes the reaction type and enthalpy change for the
forward reaction?
Reaction Type ΔH Value
A. exothermic 10 kJ
B. exothermic -10 kJ
C. endothermic 10 kJ
D. endothermic -10 kJ
25. Consider the following information for a reversible chemical reaction:
Forward activation energy 20 kJ Reverse activation energy 30 kJ
Which of the following describes the reaction type and enthalpy change for the reverse
reaction?
Reaction Type ΔH Value
A. exothermic 10 kJ
B. exothermic -10 kJ
C. endothermic 10 kJ
D. endothermic -10 kJ
26.
Which of the following is true for the forward reaction?
Reaction PE of Activated Complex (kJ) ΔH (kJ)
A. catalyzed 100 -50
B. uncatalyzed 300 -50
C. catalyzed 250 +50
D. uncatalyzed 150 -50
27. An activated complex can be described as
A. a particle of maximum KE and minimum PE.
B. a stable particle found in a reaction mechanism.
C. an unstable particle that is neither reactant nor product.
D. a particle which is first used then regenerated in a reaction mechanism.
28. Which of the following describes the Ea of a fast reaction and the stability of its
activated complex?
Ea Activated Complex
A. small unstable
B. small stable
C. large unstable
D. large stable
29. As an activated complex changes into products, what changes occur in the chemical
bonds of the activated complex and the PE of the system?
Bonds PE
A. form increases
B. form decreases
C. break increases
D. break decreases
30. As reactants change into an activated complex, what changes occur in the chemical bonds
of the activated complex and the PE of the system?
Bonds PE
A. form increases
B. form decreases
C. break increases
D. break decreases
Use this diagram for 31 -33
31. Which of the following describes the reverse reaction?
Activation Energy (kJ) ∆H (kJ)
A. uncatalyzed 200 −100
B. catalyzed 200 −100
C. uncatalyzed 300 +100
D. catalyzed 300 +100
32. Consider the following reaction:
CH4 + Cl2 → CH2Cl2 + H2
Which answer best describes the activated complex?
Formula KE relative to reactants
A. CH4 higher
B. CH4 lower
C. CH4Cl2 higher
D. CH4Cl2 lower
Consider the following reaction mechanism
Step 1: M + X → MX
Step 2: MX + A → D + X
The chemical species MX is a(n)
A. Catalyst
B. Inhibitor
C. Final Product
D. Reaction Intermediate
2. Consider the following reaction mechanism
Step 1: NO2 + NO2 → NO + NO3
Step 2: NO3 + CO → NO2 + CO2
The overall reaction is
A. 2NO2 → NO3 + NO
B. NO2 + CO → NO + CO2
C. NO3 + CO → NO2 + CO2
D. NO2 + NO3 + CO → NO3 + NO2 + NO + CO2
3. Consider the following reaction mechanism
Step 1: V3+ + Cu2+ → V4+ + Cu+ (slow)
Step 2: Cu+ + Fe3+ → Cu2+ + Fe2+ (fast)
The reaction intermediate is
A. Cu+
B. Cu2+
C. V3+
D. Fe3+
4. Consider the following reaction Mechanism
Step 1: H2O2 + I - → H2O + IO-
Step 2: H2O2 + IO - → H2O + O2 + I -
The reaction intermediate is
A. I-
B. IO -
C. H2O
D. H2O2
5. Consider the following potential energy diagram
The above potential energy diagram represents an
A. Exothermic reaction involving one step
B. Exothermic reaction involving two steps
C. Endothermic reaction involving one step
D. Endothermic reaction involving two steps
6. Consider the following reaction mechanism
Step 1: NO2(g) + NO2(g) → NO(g) + NO3(g) (slow)
Step 2: NO3(g) + CO(g) → CO2(g) + NO2(g) (fast)
Which one of the following changes would result in the greatest increase in reaction rate
A. Increase [CO]
B. Decrease [NO]
C. Increase [NO2]
D. Increase [NO3]
7. An uncatalyzed reaction was found to produce 40 kJ of energy in 10 mins. When catalyzed,
the same reaction produced 40 kJ of energy in 2 mins. Which one of the following potential
energy diagrams is consistent with the above data?
8. Consider the following reaction mechanism
Step 1: ICl + H2 → HI + HCl (slow)
Step 2: ICl + HI → HCl + I2 (fast)
The Species HCl is a
A. Product
B. Catalyst
C. Reactant
D. Reaction Intermediate
9. Consider the following reaction mechanism
Step 1: Cl(g) + O3(g) → ClO(g) + O2(g)
Step 2: O(g) + ClO(g) → Cl(g) + O2(g)
The Reaction intermediate is
A. Cl
B. O2
C. O3
D. ClO
10. In a reaction mechanism, the rate determining step is the
A. Fastest and has the lowest reaction rate.
B. Fastest and has the highest activation energy
C. Slowest and has the lowest activation energy
D. Slowest and has the highest activation energy
11. Select the true statement concerning the above potential energy diagram.
A. The catalyzed reaction has a larger ∆H
B. The uncatalyzed reaction has a larger ∆H
C. The catalyzed reaction has a greater rate of reaction
D. The uncatalyzed reaction has a greater rate of reaction
12. Which point on the diagram above represents the potential energy of the activated complex
formed in the uncatalyzed reaction?
A. I
B. II
C. III
D. IV
13. Consider the following reaction
Step 1: NO(g) + O3(g) ------ > NO2(g) + O2(g)
Step 2: O(g) + NO2(g) ------ > NO(g) + O2(g)
The catalyst is
A. O2
B. O3
C. NO
D. NO2
14. Consider the following reaction mechanism
Step 1: N2O(g) ------ > N2(g) + O(g)
Step 2: N2O(g) + O(g) ------ > N2(g) + O2(g)
The reactant in the overall reaction is
A. O
B. O2
C. N2
D. N2O
15. Consider the following reaction
O3(g) + NO(g) ----- > NO2(g) + O2(g)
NO2(g) + O(g) ------ > NO(g) + O2(g)
The product in the overall reaction is
A. O2
B. O3
C. NO
D. NO2
Use the following reaction mechanism to answer questions 16 and 17.
Step 1: 2PO → P2O2 (fast)
Step 2: P2O2 + H2 → P2O + H2O (slow)
Step 3: P2O + H2 → P2 + H2O (fast)
16. Increasing the concentration of which of the following substances would cause the
greatest increase in the reaction rate?
A. H2
B. PO
C. P2O
D. H2O
17. Which of the following are products in the overall reaction?
I P2
II P2O2
III PO2
IV H2O
A. I and II only
B. I and IV only
C. II and III only
D. III and IV only
18. The Intermediates are:
A. NO H2
B. H2O P2
C. P2O2 PO
D. P2O2 P2O
19. Which of the following could describe a catalyst?
A. A substance that increases the reaction time.
B. A substance that provides an alternate mechanism with higher activation energy.
C. A substance that is formed in one step and used up in a subsequent step in a
reaction mechanism.
D. A substance that is used up in one step and reformed in a subsequent step in
a reaction mechanism.
20. Consider the following reaction: 2PO(g) + O2(g) → 2PO2(g)
Why would this reaction probably involve more than one step?
A. There is insufficient activation energy.
B. This reaction has high activation energy.
C. Reactions between gases are typically slow.
D. A successful collision between three molecules is unlikely.
21. Consider the following reaction mechanism:
Step 1 Cl3 → Cl2 + Cl
Step 2 Cl3 + Cl → 2Cl2
Which of the following could represent the activated complex for Step 2?
A. Cl
B. Cl2
C. Cl3
D. Cl4
22. Consider the reaction: 2C4H10(g) + 13O2(g) → 8CO2(g) + 10H2O(l)
Which of the following explains, in terms of collision theory, why this reaction occurs in
more than one step?
A. a low C4H12(g) pressure
B. low temperature of reactant mixture
C. low probability of a multi-particle collision
D. particles collide with insufficient kinetic energy
23. Consider the following reaction mechanism and overall reaction:
Step 1 ½ O2(g) + NO(g) → NO2(g)
sunlight
Step 2 NO2(g) → NO(g) + O(g)
Step 3 O2(g) + O(g) → O3(g)
Overall 3/2 O2 (g) → O3(g)
What is the catalyst in this mechanism?
A. O
B. NO
C. NO2
D. sunlight
24. What is an intermediate in this mechanism?
A. O
B. NO
C. O3
D. sunlight
25. Consider the following reaction mechanism:
Step 1 NOI → NO + I
Step 2 NOI + I → NOI2
Identify the reaction intermediate.
A. I
B. NOI2
C. NO
D. NOI
26. Consider the following reaction mechanism:
Step 1 2NO2 → NO3 + NO
Step 2 NO3 + CO → NO2 + CO2
Identify a product in the overall reaction.
A. CO
B. CO2
C. NO2
D. NO3
27. Consider the following reaction mechanism:
Step 1 2NO2 → NO3 + NO
Step 2 NO3 + CO → NO2 + CO2
Identify an intermediate.
A. CO
B. CO2
C. NO2
D. NO3
Drano®, a commercial product used to clean drains, contains small bits of aluminum metal and
A. ammonia
B. acetic acid
C. hydrochloric acid
D. sodium hydroxide
2. A net ionic equation for the reaction between CH3COOH and KOH is
A. CH3COOH(aq) + K+(aq) ⇄ CH3COOK(aq)
B. CH3COOH(aq) + OH-(aq) ⇄ H2O(l) + CH3COO-(aq)
C. CH3COOH(aq) + KOH(aq) ⇄ H2O(l) + CH3COOK(aq)
D. CH3COOH(aq) + K+(aq) + OH-(aq)⇄ H2O(l) + KCH3COO(aq)
3. Which equation represents a neutralization reaction?
A. Pb2+(aq) + 2Cl-(aq) → PbCl2(s)
B. HCl(aq) + NH3(aq) → NH4Cl(aq)
C. BaI2(aq) + MgSO4(aq) → BaSO4(s) + MgI2(aq)
D. MnO4-(aq) + 5Fe2+(aq) +8H+(aq) → Mn2+(aq) + 5Fe3+(aq) + 4H2O(l)
4. An Arrhenius acid is a substance that
A. accepts a proton
B. donates a proton
C. produces H+ in solution
D. produces OH- in solution
5. Consider the following data table:
Breaker Volume Contents
1 15 mL 0.1 M Sr(OH)2
2 20 mL 0.2 M NH4OH
3 25 mL 0.1 M KOH
4 50 mL 0.2 M NaOH
Identify the beaker that requires the smallest volume of 1.0 M HCl for complete
neutralization
A. Beaker 1
B. Beaker 2
C. Beaker 3
D. Beaker 4
6. The net ionic equation for the titration of HClO4(aq) with LiOH(aq) is
A. H+(aq) + OH-(aq) → H2O(l)
B. HClO4(aq) + OH-(aq) → ClO4-(aq) + H2O(l)
C. HClO4(aq) + LiOH(aq) → LiClO4(aq) + H2O(l)
D. H+(aq) + ClO4-(aq) + Li+(aq) + OH-(aq) → LiClO4(aq) + H2O(l)
7. The equilibrium constant expression for a sulphurous acid is
A Ka = [H+][HSO3-]
B. Ka = [H+][HSO3-]
[H2SO3]
C. Ka = [2H+][SO32-]
[H2SO3]
D. Ka = [H+][SO32-]
[H2SO3]
8. To distinguish between a strong acid and a strong base, an experimenter could use
A. odor
B. magnesium
C. a conductivity test
D. the common ion test
9. How many acids from the list below are known to be weak acids?
HCl, HF, H2SO3, H2SO4, HNO3, HNO2
A. 2
B. 3
C. 4
D. 5
10. There are two beakers on a laboratory desk. One beaker contains 1.0 M HCl and
the other contains tap water. To distinguish the acid solution from the water, one
would use
A. a piece of copper.
B. a piece of magnesium
C. phenolphthalein indicator
D. a piece or red litmus paper
11. Caustic soda, NaOH, is found in
A. fertilizers
B. beverages
C. toothpaste
D. oven cleaners
12. Which of the following is the strongest acid?
A. Acetic acid
B. Oxalic acid
C. Benzoic acid
D. Carbonic acid
13. The acid used in the lead-acid storage battery is
A. HCl
B. HNO3
C. H2SO4
D. CH3COOH
14. A definition for a Brønsted-Lowry acid should contain which of the following
phrases?
A. the donation of H+
B. the donation of OH-
C. the acceptance of H+
D. the acceptance of OH-
15. What species will form when H+ ions are in the presence of H2O molecules?
A. HO+
B. HO2+
C. H3O+
D. H2O2
16. What is the conjugate acid of the base HAsO42-?
A. AsO43-
B. H2AsO42-
C. H2AsO4-
D. H3AsO4
17. What species is the hydronium ion?
A. HO+
B. HO2+
C. H2O2
D. H3O+
18. Which of the following is a characteristic of acidic solutions?
A. They accept H+ ions.
B. They have a pH more than 7.
C. They react with Mg to produce H2 gas.
D. They turn limus blue.
19. Which of the following is a common base found in drain cleaners?
A. bleach
B. vinegar
C. milk of magnesia
D. sodium hydroxide
20. Which of the following is a characteristic of basic solutions?
A. They donate H+ ions.
B. They have a pH less than 7.
C. They feel slippery.
D. They turn limus red.
21. Which of the following is the weakest acid?
A. Acetic acid
B. Oxalic acid
C. Benzoic acid
D. Carbonic acid
22. What is the main difference between a strong acid and a weak acid?
A. their degree of ionization
B. their reactivity with platinum
C. their concentration in solution
D. their effect on an indicator
23. Which of the following best describes an acidic solution?
Litmus Colour Reaction with Zn
A. red reaction
B. red no reaction
C. blue no reaction
D. blue reaction
24. Identify the common acid found in the stomach.
A. benzoic acid
B. sulphuric acid
C. perchloric acid
D. hydrochloric acid
25. Which of the following best describes an basic solution?
Litmus Colour pH
A. red less than 7
B. red more than 7
C. blue less than 7
D. blue more than 7
26. Which of the following is a general characteristic of Arrhenius acids?
A. They produce H+ in solution.
B. They accept an H+ from water.
C. They turn bromothymol blue a blue colour.
D. They react with H3O+ ions to produce H2.
27. Identify a conjugate pair from the equilibrium provided:
PO43- + HCO3- ⇌ HPO42- + CO32-
A. CO32- and HPO42-
B. PO43- and HCO3-
C. PO43- and HPO42-
D. HCO3- and HPO42-
28. Which of the following best describes a weak acid?
A. pH = 10
B. It may be very soluble, but only partly ionized.
C. It must be very soluble and completely ionized.
D. It must be of low solubility and completely ionized.
29. Which of the following is a common property of acid solutions?
A. They have a pH > 7.
B. They turn red litmus blue.
C. They have a slippery feeling.
D. They turn pink phenolphthalein colourless.
30. What is a general characteristic of bases?
A. They all donate H+.
B. They all accept OH- .
C. They will neutralize acids
D. They will react with acids to produce H2 gas.
When a catalyst is added to an equilibrium system, the forward reaction
A. Increases and the reverse decreases
B. Decreases and the reverse decreases
C. Decreases and the reverse increases
D. Increases and the reverse increases
2. Consider the following concentration versus time graph for the equilibrium
N2O4(g) ⇄ 2NO2(g)
“t” TIME(S)
At time= “t”, which one of the following stresses occurred
A. Catalyst was added
B. Pressure was changed
C. Temperature was changed
D. Concentration of NO2 was changed
3. Which of the following reactions will shift left when pressure is increased and when
temperature is decreased?
A. N2(g) + 2O2(g) + heat ⇄ 2NO2(g)
B. N2(g) + 3H2(g) ⇄ 2NH3(g) + heat
C. CH4(g) + H2O(g) + heat ⇄ CO(g) + 3H2(g)
D. CS2(g) + 4H2(g) ⇄ CH4(g) + 2H2S(g) + heat
4. Consider the following graph, which relates to this equilibrium
N2(g) + 3H2(g) ⇄ 2NH3(g) ∆H = -92kJ
Which of the following caused the changes in the concentrations at time t ?
A. Addition of N2
B. Removal of H2
C. Decrease in temperature
D. Decrease in reaction volume
5. Consider the following equilibrium: CH4(g) + H2O(g) + heat ⇄ CO(g) + 3H2(g)
In which of the following will both stresses shift the equilibrium right
A. A decrease in temperature and a decrease in volume
B. An increase in temperature and a decrease in volume
C. A decrease in temperature and an increase in volume
D. An increase in temperature and an increase in volume
6. Consider the following equilibrium system: N2(g) + 3H2(g) ⇄ 2NH3(g) + 92 kJ
In order to maximize the yield for this reaction, the best conditions are:
A. Low pressure and low temperature
B. Low pressure and high temperature
C. High temperature and low pressure
D. High pressure and low temperature
7. Consider the following equilibrium system: NH3(aq) + H2O(l) ⇄ NH+4(aq) + OH--(aq)
Which of the following when added to the above equilibrium system would cause an
increase in [ OH-]
A. NH3
B. H2O
C. NH4+
D. HCl
8. Consider the following reversible reaction: Fe3+(aq) + SCN-(aq) ⇄ FeSCN2+(aq)
A solution of Fe(NO3)3 is added to a solution of KSCN. Which one of the following
statements
describes the changes in forward and reverse reaction rates as the reaction moves towards
equilibrium?
A. Forward and reverse rates increase
B. Forward and reverse rates decrease
C. Forward rate increases and reverse rate decrease
D. Forward rate decreases and reverse rate increase
9. Consider the following equilibrium: N2(g) + O2(g) ⇄ 2NO(g) ∆H= + 181 kJ
When the temperature is decreased, the equilibrium
A. Shifts left and [NO] decreases
B. Shifts left and [NO] increases
C. Shifts right and [NO] increases
D. Shifts right and [NO] decreases
10. Consider the following equilibrium: N2(g) + 3H2(g) ⇄ 2NH3(g) + 92 kJ
In which of the following will both changes shift the equilibrium right?
A. An increase in volume and a decrease in temperature
B. An increase in volume and a increase in temperature
C. A decrease in volume and a decrease in temperature
D. A decrease in volume and an increase in temperature
11. Consider the following equilibrium: CaCO3(s) + 556 kJ ⇄ CaCO(s) + CO2(g)
The equilibrium will shift to the right
A. CO2 is added
B. CaCO3(s) is added
C. The temperature is increased
D. The temperature is decreased
12. Consider the following equilibrium: SO2(g) + NO2(g) ⇄ SO3(g) + NO(g) + energy
The equilibrium does not shift with a change in the
A. Volume
B. Temperature
C. Concentration of products
D. Concentration of reactants
13. Consider the following equilibrium: 2Hl(g) ⇄ H2(g) + I2(g)
At constant temperature and volume, more I2 is added to the above equilibrium.
A new state of equilibrium results from a shift to the
A. Left with a net decrease in [H2]
B. Left with a net increase in [H2]
C. Right with a net increase in [H2]
D. Right with a net decrease in [H2]
14. Consider the following diagram for the equilibrium system:
Energy + N2O4(g) ⇄ 2NO2(g)
A. [NO2] was increased.
B. [N2O4] was decreased.
C. Temperature was increased.
D. Temperature was decreased.
15. Consider the following diagram for the equilibrium system:
Energy + N2O4(g) ⇄ 2NO2(g)
A. [NO2] was increased.
B. [N2O4] was decreased.
C. Temperature was increased.
D. Temperature was decreased.
16. Consider the following diagram for the equilibrium system:
Energy + N2O4(g) ⇄ 2NO2(g)
A. [NO2] was increased.
B. [N2O4] was decreased.
C. Temperature was increased.
D. The Volume was decreased.
17. Which of the following describes the temperature and pressure needed for
the maximum yield of NO2?
Energy + N2O4(g) ⇄ 2NO2(g)
Temperature Pressure
A. low low
B. low high
C. high low
D. high high
18. Which of the following describes the temperature and pressure needed for
the maximum yield of NH3?
N2(g) + 3H2(g) ⇄ 2NH3(g) + 92 kJ
Temperature Pressure
A. low low
B. low high
C. high low
D. high high
19. Which of the following describes the temperature and pressure needed for
the maximum yield of CO2?
CaCO3(s) ⇄ CaCO(s) + CO2(g) ΔH = +215 kJ
Temperature Pressure
A. low low
B. low high
C. high low
D. high high
20. Consider the following equilibrium: CaCO3(s) ⇌ CaO(s) + CO2(g) ΔH = +160 kJ
Which starting materials could establish an equilibrium?
1 CaCO3(s) 2 CaO(s)
3 CaO(s) and CO2(g) 4 CaCO3(s) and CO2(g)
A. 1, 2, 3 only
B. 1, 2, 4 only
C. 1, 3, 4 only
D. 3, 4 only
Consider the following reaction for the next five questions 21 to 25.
4NH3(g) + 3O2(g) ⇌ 2N2(g) + 6H2O(l) + 1250 kJ
21. Which of the following would cause the concentration of NH3 at equilibrium to increase?
A. an increase in [O2]
B. a increase in volume
C. a decrease in temperature
D. an increase in temperature
22. What happens when NH3 is added to the above system?
Equilibrium [N2]
A. no shift unchanged
B. shifts right decreases
C. shifts right increases
D. shifts left increases
23. If some O2 is removed from the system, what happens to the forward and
reverse reaction rates after equilibrium is re-established?
Forward Reaction Rate Reverse Reaction Rate
A. increases decreases
B. decreases decreases
C. increases increases
D. decreases increases
24. If some O2 is injected into the system, what happens to the forward and
reverse reaction rates during the shift to re-establish equilibrium?
Forward Reaction Rate Reverse Reaction Rate
A. increases decreases
B. decreases decreases
C. increases increases
D. decreases increases
25. Consider the equilibrium: N2(g) + 3H2(g) ⇄ 2NH3(g) + 92 kJ
The following diagram represents the rate of the reverse reaction.
t1
Which of the following stresses explains what happened at t1 ?
A. [H2] increased.
B. [N2] decreased.
C. [NH3] increased.
D. [NH3] decreased.
26. Consider the equilibrium: N2(g) + 3H2(g) ⇄ 2NH3(g) + 92 kJ
The following diagram represents the rate of the forward reaction.
t1
Which of the following stresses explains what happened at t1 ?
A. [H2] increased.
B. temperature was lowered
C. [NH3] increased.
D. [NH3] decreased.
27. Consider the equilibrium: N2(g) + 3H2(g) ⇄ 2NH3(g) + 92 kJ
The following diagram represents the rate of the reverse reaction.
t1
Which of the following stresses explains what happened at t1 ?
A. [H2] increased.
B. [N2] decreased.
C. [NH3] increased.
D. [NH3] decreased.
28. A small amount of NaOH is added to the following equilibrium system:
2CrO42- + 2H+ ⇌ Cr2O72-(aq) + H2O(l)
How do the [CrO42-] and the reverse reaction rate change as equilibrium is re-established?
[CrO42-] Reverse Rate
A. increases increases
B. increases decreases
C. decreases decreases
D. decreases increases
29. A small amount of H2SO4 is added to the following equilibrium system:
2CrO42- + 2H+ ⇌ Cr2O72-(aq) + H2O(l)
How do the [CrO42-] and the reverse reaction rate change as equilibrium is re-established?
[CrO42-] Reverse Rate
A. increases increases
B. increases decreases
C. decreases decreases
D. decreases increases
30. A small amount of NaOH is added to the following equilibrium system:
2CrO42- + 2H+ ⇌ Cr2O72-(aq) + H2O(l)
How do the [Cr2O72-] and the reverse reaction rate change as equilibrium is re-
established?
[Cr2O72-] Reverse Rate
A. increases increases
B. increases decreases
C. decreases decreases
D. decreases increases
31. A small amount of H2SO4 is added to the following equilibrium system:
2CrO42- + 2H+ ⇌ Cr2O72-(aq) + H2O(l)
How do the [Cr2O72-] and the reverse reaction rate change as equilibrium is re-
established?
[Cr2O72-] Reverse Rate
A. increases increases
B. increases decreases
C. decreases decreases
D. decreases increases
The equilibrium constant expression for the following reaction is:
2Hg(l) + O2(g) ⇄ 2HgO(s)
A. Keq = 1/[O2]
B. Keq = [O2]
C. Keq = [2HgO] / [O2] [2Hg]
D. Keq = [HgO]2 / [Hg]2[O2]
2. Identify the equilibrium system that least favors the formation of products
A. 2HgO ⇄ 2Hg + O2 Keq = 1.2 x 10-22
B. CH3COOH + H2O ⇄ H3O+ + CH3COO- Keq = 1.8 x 10-5
C. 2NO + O2 ⇄ 2NO2 Keq = 6.5 x 105
D. H2 + Cl2 ⇄ 2HCl Keq = 1.8 x 1033
3. Consider the following equilibrium system: 3O2(g) ⇄ 2O3(g) Keq = 1
Which equation compares the concentration of oxygen and ozone?
A. [O2] = [O3]2/3
B. [O2] = [O3]
C. [O2] = [O3]3/2
D. [O2] 2/5 = [O3]
4. For which of the following equilibrium does Keq = [O2]
A. O2(l) ⇄ O2(g)
B. 2O3(g) ⇄ 3O2(g)
C. 2H2O(l) ⇄ 2H2(g) + O2(g)
D. 2Hg(s) + O2(g) ⇄ 2HgO(s)
5. Consider the following equilibrium system at 25O C : 2SO2(g) + O2(g) ⇄ 2SO3(g)
At equilibrium, [SO2] is 4.00 x 10-3 mol/L, [O2] = 4.00 x 10-3 mol/L and
[SO3] is 2.33 x 10-3 mol/L. From this data, the Keq value for the above system is
A. 6.85 x 10-3
B. 1.18 x 10-2
C. 84.8
D. 146
6. Consider the following equilibrium system: PCl5(g) ⇄ PCl3(g) + Cl2(g)
At equilibrium, [PCl5] is a 0.400 M. [PCl3] is 1.50 M and [Cl2] is 0.600 M.
The Keq for the reaction is
A. 0.360
B. 0.444
C. 0.900
D. 2.25
7. Consider the following equilibrium: 2H2S(g) ⇄ 2H2(g) + S2(g)
At equilibrium, [H2S] = 0.50 mol/L. [H2] = 0.10 mol/L and [S2] = 0.40 mol/L.
The value of Keq is calculated using the ratio
A (0.10)(0.40)
(0.50)
B. (0.10)2(0.40)
(0.50)2
C. (0.50)
(0.10)(0.50)
D. (0.50)2
(0.10)2(0.40)
8. Consider the following equilibrium: 2NO(g) + Cl2(g) ⇄ 2NOCl(g) Keq = 12
At equilibrium, [NOCl] = 1.60 mol/L and [NO] = 0.80 mol/L. The [Cl2] is
A. 0.17 mol/L
B. 0.27 mol/L
C. 0.33 mol/L
D. 3.0 mol/L
9. Consider the following equilibrium: I2(s) + H2O(l) ⇄ H+(aq) + I-(aq) + HOI(aq)
The equilibrium constant expression for the above system is
A. Keq = [H+][I-]
B. Keq = [H+][I-][HOI]
C. Keq = [H+][I-][HOI]
[I2][H2O]
D. Keq = [H+][I-][HOI]
[H2O]
10. Consider the following equilibrium: 2CO(g) + O2(g) ⇄ 2CO2(g)
The ratio used to calculate the equilibrium constant is
A. [2CO]2[O2]
[2CO2]2
B. [2CO2]2
[2CO]2[O2]
C. [CO]2[O2]
[CO2]2
D. [CO2]2
[CO]2[O2]
11. Consider the following equilibrium: 2Fe(s) + 3H2O(g) ⇄ Fe2O3(s) + 3H2(g)
The equilibrium constant expression is
A. Keq = [Fe2O3][H2]3
[Fe]2[H2O]3
B. Keq = [Fe2O3][3H2]
[2Fe] [3H2O]
C. Keq = [H2]3
[H2O]3
D. Keq = [H2]3
12. Consider the following equilibrium: N2O4(g) ⇄ 2NO2(g) Keq = 0.133
At equilibrium, the [N2O4] is equal to
A. 0.133
[NO2]
B. [NO2]
0.133
C. 0.133
[NO2]2
D. [NO2]2
0.133
13. Consider the following equilibrium: 4KO2(s) + 2H2O(g) ⇄ 4KOH(s) + 3O2(g)
The equilibrium constant expression is
A. Keq = [KOH]4[O2]3
[KO2]4[H2O]2
B. Keq = [O2]3
[H2O]2
C. Keq = [KO2]4[H2O]2
[KOH]4[O2]3
D. Keq = [H2O]2
[O2]3
14. Consider the following equilibrium: C(s) + H2O(g) ⇄ CO(g) + H2(g)
The contents of a 1.00 L container at equilibrium were analyzed and found to
contain 0.20 mol C, 0.20 mol H2O, 0.60 mol CO and 0.60 mol H2. The equilibrium
constant is
A. 0.11
B. 0.56
C. 1.8
D. 9.0
15. Consider the following equilibrium: N2O4(g) ⇄ 2NO2(g) Keq = 4.61 x 10-3
A 1.00 L container at equilibrium was analyzed and found to contain 0.0200 moles NO2.
At equilibrium, the concentration of N2O4 is
A. 0.0868 mol/L
B. 0.230 mol/L
C. 4.34 mol/L
D. 11.5 mol/L
16. Consider the following equilibrium: CH4(g) + H2O(g) ⇄ CO(g) + 3H2(g) Keq= 5.7
At equilibrium, the [CH4] = 0.40 mol/L [CO] = 0.30 mol/L and [H2] = 0.80 mol/L.
The [H2O] is
A. 0.067 mol/L
B. 0.11 mol/L
C. 2.2 mol/L
D. 5.3 mol/L
17. Consider the following equilibrium: H2(g) + I2(g) ⇄ 2HI(g)
At equilibrium, the [H2] = 0.020 mol/L. [I2] = 0.020 mol/L and [HI] = 0.160 mol/L.
The value of the equilibrium constant is
A. 2.5 x 10-3
B. 1.6 x 10-2
C. 6.4 x 101
D. 4.0 x 102
18. Consider the following constant expression: Keq = [CO2]. Which one of the following
equilibrium systems does the above expression represent?
A. CO2(g) ⇄ CO2(s)
B. PbO(s) + CO2(g) ⇄ PbCO3(s)
C. CaCO3(s) ⇄ CaO(s) + CO2(g)
D. H2CO3(aq) ⇄ H2O(l) + CO2(aq)
19. Given the following equilibrium system: Br2(g) ⇄ Br2(l)
The equilibrium constant expression for the above system is
A. Keq = [Br2(l)]
[Br2(g)]
B. Keq = [Br2(g)]
C. Keq = 1 __
[Br2(g)]
D. Keq = [Br2(g)] [Br2(g)]
20. Consider the following equilibrium: CO(g) + 2H2(g) ⇄ CH3OH(g) + 91 kJ
A change in temperature of the above system increases the value of the equilibrium
constant.
The new state of equilibrium was established by a shift
A. Left as a result of a decrease in temperature
B. Right as a result of a decrease in temperature
C. Left as a result of an increase in temperature
D. Right as a result of an increase in temperature
21. Consider the equilibrium: SrCO3(s) ⇌ SrO(s) + CO2(g) In a 2.5 L container
at equilibrium there are 2.42 g CO2, 1.00 g SrCO3 and 1.00 SrO.
Which of the following is the value of Keq?
A. 0.022
B. 0.011
C. 0.020
D. 91
22. Consider the following equilibrium: CCl4(g) ⇌ C(s) + 2Cl2(g)
Initially, 0.62 mol CCl4 was placed in a 2.0L container. At equilibrium, [Cl2] = 0.060
M.
Which of the following is the value of Keq?
A. 0.00039
B. 0.013
C. 0.014
D. 0.78
23. Consider the following equilibrium: CH4(g) + H2O(g) ⇌ CO(g) + 3H2(g)
At equilibrium, 1.20 mol CH4, 1.20 mol H2O, 0.080 mol CO and 0.040 mol H2
are present in a 2.0 L container. What is the value of Keq ?
A. 4.3 x 10-6
B. 2.2 x 10-2
C. 2.2 x 10-4
D. 8.9 x 10-7
24. Consider the following equilibrium: Cr2O72-(aq) + 2OH-(aq) ⇌ 2CrO42-(aq) + H2O(l)
The concentration of ions at equilibrium was measured at a specific temperature and
found to be
[CrO42-] = 0.100 M, [Cr2O72-] = 0.20 M, and [OH-] = 0.11 M. What is the Keq?
A. 41
B. 4.13
C. 0.83
D. 0.11
25. Consider the following equilibrium: Cr2O72-(aq) + 2OH-(aq) ⇌ 2CrO42-(aq) + H2O(l)
Keq = 4.14
The concentration of ions at equilibrium was measured at a specific temperature and
found to be
[Cr2O72-] = 0.100 M and [OH-] = 0.20 M. What is the equilibrium [CrO42-] ?
A. 0.017 M
B. 0.083 M
C. 0.13 M
D. 0.32 M
26. Consider the following equilibrium: 2COF2(g) ⇌ CO2(g) + CF4(g) Initially, 0.32 M CO2
and 0.40 M CF4
are placed in a container. At equilibrium, it is found that the [COF2] is 0.16 M. What is
the value of Keq?
A. 0.026
B. 1.5
C. 9.3
D. 3.0
27. Consider the following equilibrium: Cr2O72-(aq) + 2OH-(aq) ⇌ 2CrO42-(aq) + H2O(l)
Keq = 4.14
The concentration of ions at equilibrium was measured at a specific temperature and
found to be
[CrO42-] = 0.100 M and [OH-] = 0.20 M. What is the equilibrium [Cr2O72-] ?
A. 0.060 M
B. 0.083 M
C. 0.13 M
D. 0.32 M
28. Consider the following equilibrium: Cr2O72-(aq) + 2OH-(aq) ⇌ 2CrO42-(aq) + H2O(l)
Keq = 4.14
The concentration of ions at equilibrium was measured at a specific temperature and
found to be
[CrO42-] = 0.100 M and [Cr2O72-] = 0.20 M. What is the equilibrium [OH-]?
A. 0.012 M
B. 0.083 M
C. 0.13 M
D. 0.11 M
29. Consider the following equilibrium: 2COF2(g) ⇌ CO2(g) + CF4(g) Initially, 0.16 M CO2
and 0.20 M CF4
are placed in a container. At equilibrium, it is found that the [COF2] is 0.080 M. What is
the value of Keq?
A. 0.12
B. 1.5
C. 8.0
D. 3.0
30. Consider the following equilibrium: CH4(g) + H2O(g) ⇌ CO2(g) + 3H2(g) Keq =
5.67
An equilibrium mixture of this system was found to contain the following concentrations:
[CH4] = 0.59 M , [H2O] = 0.63 M, [CO2] = 0.25 M.
What was the equilibrium [H2] ?
A. 0.26 M
B. 0.64 M
C. 2.0 M
D. 8.4 M
31. Consider the following equilibrium: 2COF2(g) ⇌ CO2(g) + CF4(g)
Initially, 0.32 M CO2 and 0.40 M CF4 are placed in a container. At equilibrium, it is found
that the [COF2] is 0.16 M.
What is the value of Keq?
A. 0.026
B. 1.5
C. 9.3
D. 3.0
32. Consider the following equilibrium: CCl4(g) ⇌ C(s) + Cl2(g)
Initially, 0.62 mol CCl4 was placed in a 2.0L container.
At equilibrium, [Cl2] = 0.060 M. Which of the following is the value of Keq?
A. 0.00039
B. 0.24
C. 0.014
D. 0.78
33. Consider the following equilibrium: 2COF2(g) ⇌ CO2(g) + CF4(g)
Initially, 0.16 M CO2 and 0.20 M CF4 are placed in a container.
At equilibrium, it is found that the [COF2] is 0.080 M.
What is the value of Keq?
A. 0.12
B. 1.5
C. 8.0
D. 3.0
Consider the following equilibrium: N2(g) + O2(g) ⇄ 2NO(g) Keq = 0.010
Initially, a 1.0 L container is filled with 0.40 mol of N2, 0.10 mol of O2 and 0.080 mol of
NO.
As the system approaches equilibrium, the
A. [NO], [N2] and [O2] remain unchanged
B. [NO] increases and both [N2] and [O2] decrease
C. [NO] decreases and both [N2] and [O2] increase
D. [NO] decreases and both [N2] and [O2] remain unchanged
2. Consider the following equilibrium: 2O2(g) + N2(g) ⇄ N2O4(g)
When 2.0 mol of O2 and 3.0 mol of N2 were placed in a 10.0 L container at 25oC, the
value of Keq=0.90.
If the same number of moles of reactant were placed in a 5.0 L container at 25oC, the
equilibrium constant would be
A. 0.011
B. 0.45
C. 0.90
D. 1.80
3. Consider the following equilibrium system: H2O(g) + CO(g) ⇄ H2(g) + CO2(g)
Initially, 5.0 moles of H2O and 4.0 moles of CO were reacted. At equilibrium, it is found
that 2.0 moles of H2 are present. How many moles of H2O remain in the mixture?
A. 1.0 moles
B. 2.0 moles
C. 3.0 moles
D. 4.0 moles
4. Consider the following equilibrium: PCl5(g) ⇄ PCl3(g) + Cl2(g) Keq=33.3
Predict what will occur when 2.0 mol of PCl5, 3.0 mol of PCl3 and 4.0 mol of Cl2
are placed in a 1.0 L container and allowed to establish equilibrium.
A. [PCl5] will increase
B. [PCl3] and [CL2] will both increase
C. [PCl5] and [Cl2] will both increase
D. [PCl5] and [PCl3] will both decrease
5. Consider the following equilibrium: CO(g) + 2H2(g) ⇄ CH3OH(g) ∆H= -18kJ
In order to increase the value of Keq for this reaction, you could
A. Increase [CO]
B. Increase the volume
C. Decrease [CH3OH]
D. Decrease the temperature
6. Consider the following: SO2Cl2(g) ⇄ SO2(g) + Cl2(g)
A 1.0 L container is initially filled with 2.0 mol of SO2Cl2.
As the reaction proceeds towards equilibrium, the rate of the forward reaction
A. Increases and the [SO2] increases
B. Increases and the [SO2] Decreases
C. Decreases and the [SO2] increases
D. Decreases and the [SO2] decreases
7. Consider the following: 2NO2(g) ⇄ N2O2(g) Keq=1.20
A 1.0 L of flask is filled with 1.4 mol NO2 and 2.0 mol N2O4.
To reach equilibrium, the reaction proceeds to the
A. Left as Trial Keq > Keq
B. Left as Trial Keq < Keq
C. Right as Trial Keq > Keq
D. Right as Trial Keq < Keq
8. Consider the following: 2C(s) + O2(g) ⇄ 2CO(g)
A 1.0 L flask is initially filled with 2.00 mol C and 0.500 mol O2.
At equilibrium, the [O2] is 0.250 mol/L. The Keq value is
A. 0.444
B. 1.00
C. 2.00
D. 2.25
9. Consider the following: 2H2O(g) ⇄ 2H2(g) + O2(g)
When 0.1010 mol H2O is placed in a 1.000 L container, equilibrium is established.
The equilibrium concentration of O2 is 0.0010 mol/L. the equilibrium concentrations of
H2O and H2 are
[H2O] [H2]
A 0.0990 0.0020
B 0.1000 0.0010
C 0.1005 0.0005
D 0.1010 0.0020
10. Which of the following equilibrium systems most favors the products?
A. Cl2(g) ⇄ 2Cl(g) Keq=6.4 x 10-39
B. Cl2(g) + 2NO(g) ⇄ 2NOCl(g) Keq=3.7 x 108
C. Cl2(g) + 2NO2(g) ⇄ 2NO2Cl(g) Keq=1.8
D. 2HCl(g) ⇄ H2(g) + Cl2(g) Keq=2.0 x 10-3
11. Consider the following equilibrium: H2O(g) + Cl2O(g) ⇄ 2HOCl(g) Keq= 9.0 x 10-2
A 1.0 L flask contains a mixture of 1.8 x 10-1 mol H2O. 4.0 x 10-4 mol Cl2O, and 8.0 x 10-2
mol HOCl .
To establish equilibrium, the system will proceed to the
A. Left as Trial Keq > Keq
B. Left as Trial Keq < Keq
C. Right as Trial Keq > Keq
D. Right as Trial Keq < Keq
12. Consider the following equilibrium: 2O3(g) ⇄ 3O2(g) Keq=55
If 0.060 mol of O3 and 0.70 mol of O2 are introduced into a 1.0 L vessel, the
A. Ktrial > Keq and the [O2] increases
B. Ktrial < Keq and the [O2] increases
C. Ktrial > Keq and the [O2] decreases
D. Ktrial < Keq and the [O2] decreases
13. Consider the following equilibrium: CO(g) + Cl2(g) ⇄ COCl2(g)
At equilibrium, a 2.0 L sample was found to contain 1.00 mol CO, 0.500 mol Cl2
and 0.100 mol COCl2. The Keq value for the above system is
A. 0.40
B. 0.20
C. 2.5
D. 5.0
14 Consider the following equilibrium: 2SO2(g) + O2(g)⇄ 2SO3(g) Keq=4.0
In an experiment, 0.40 mol SO2(g), 0.20 mol O2(g) and 0.40 mol SO3(g) are placed into a
1.0 liter container. Which of the following statements relates the changes in [SO2] and
[O2]
as equilibrium becomes established?
A. The [SO2] and [O2] increase
B. The [SO2] and [O2] decrease
C. The [SO2] and [O2] do not change
D. The [SO2] increases and the [O2] decreases
15. Consider the following equilibrium system: H2(g) + S(s) ⇄ H2S(g)
In a 1.0 L container at equilibrium there are 0.050 mol H2, 0.050 mol S and 1.0 mol H2S.
The value of Keq is
A. 2.5 x 10-3
B. 5.0 x 10-2
C. 2.0 x 101
D. 4.0 x 102
16. Consider the following equilibrium and experimental data:
N2O4(g) ⇄ 2NO2(g)
Initial Equilibrium
[N2O4] [NO2] [N2O4] [NO2]
Trial 1 0.0400 M 0.0000 M 0.0337 M 0.0125 M
Trial 2 0.0200 M 0.0600 M 0.0429 M 0.0141 M
Which of the following represents the Keq value?
A. 0.00464
B. 0.371
C. 0.742
D. 216
17. Consider the following equilibrium: Cl2(g) + 2NO(g) ⇌ 2NOCl(g) Keq = 5.0
At equilibrium, [Cl2] = 1.0 M and [NO] = 2.0 M.
What is the [NOCl] at equilibrium?
A. 0.80 M
B. 0.89 M
C. 4.5 M
D. 10 M
18. Consider the following equilibrium: Cl2(g) + 2NO(g) ⇌ 2NOCl(g)
If 12.0 moles of Cl2, 10.24 moles of NO, and 2.00 moles NOCl are placed in a
2.00 L container and the system moves to the right to get to equilibrium,
If there are 10.0 moles NOCl at equilibrium, calculate the Keq.
A. 0.996
B. 5.58
C. 1.12
D. 4.98
19. What will cause the value of Keq for an exothermic reaction to decrease?
A. increasing the pressure
B. increasing the temperature
C. decreasing the temperature
D. decreasing the surface area
20. Consider the following: H2(g) + I2(g) ⇌ 2HI(g)
Initially, some HI is placed into a 1.0 L container. At equilibrium there are 0.010 mol H2,
0.010 mol I2 and 0.070 mol HI present. How many moles of HI were initially added to
the container?
A. 0.060 mol
B. 0.070 mol
C. 0.080 mol
D. 0.090 mol
21. Consider the following equilibrium: 3NO2(g) ⇌ N2O5(g) + NO(g).
Initially, some NO2, N2O5 and NO were placed in a container and allowed to reach
equilibrium.
When equilibrium was established, it was found that the pressure had increased.
Which of the following explains what happened?
A. Trial Keq > Keq so the system shifted left.
B. Trial Keq < Keq so the system shifted left.
C. Trial Keq > Keq so the system shifted right.
D. Trial Keq < Keq so the system shifted right.
22. Consider the following equilibrium: 3NO2(g) ⇌ N2O5(g) + NO(g).
Initially, 8.00 moles NO2 were placed in a 2.0 L container and allowed to reach
equilibrium.
The equilibrium concentration of NO was 1.10 M. Calculate the Keq.
A. 1.7
B. 1.9
C. 3.5
D. 0.050
23. Consider the following equilibrium: 3NO2(g) ⇌ N2O5(g) + NO(g).
At a different temperature, 4.00 M NO2 were placed in a 2.0 L container and
allowed to reach equilibrium. The equilibrium concentration of NO2 was 1.00 M.
Calculate the Keq.
A. 0.11
B. 1.0
C. 3.0
D. 10.
24. Consider the reaction: 2HBr(g) ⇌ H2(g) + Br2(g) Keq = 49.0
If 4.0 M HBr is initially placed into a container, what will be the equilibrium [HBr]?
A. 0.27 M
B. 3.7 M
C. 5.3 M
D. 8.8 M
25. Consider the reaction: 2HBr(g) ⇌ H2(g) + Br2(g) Keq = 49.0
If 0.120 M H2, 0.120 M Br2 and 0.01714 M HBr are placed into a container at
440 C, which of the following is true as equilibrium is approached?
A. [Br2] decreases significantly.
B. [HBr] decreases significantly.
C. [H2] decreases significantly.
D. [H2] remains the same.
26. Consider the reaction: 2HBr(g) ⇌ H2(g) + Br2(g) Keq = 49.0
If 1.20 M H2, 1.20 M Br2 and 1.00 M HBr are placed into a container at
440 C, which of the following is true as equilibrium is approached?
A. [Br2] decreases significantly.
B. [HBr] decreases significantly.
C. [H2] decreases significantly.
D. [H2] remains the same.
27. Which Keq is most likely to favour the formation of reactants?
A. Keq = 1.65 x 104
B. Keq = 5.69 x 10-11
C. Keq = 3.95 x 10-11
D. Keq = 7.67 x 104
28. Which Keq is most likely to favour the formation of products?
A. Keq = 1.65 x 10-4
B. Keq = 5.69 x 10-11
C. Keq = 3.95 x 10-11
D. Keq = 7.67 x 10-4
29. Consider the following equilibrium system: 2NO(g) + Cl2(g) ⇌ 2NOCl(g) + 25 kJ
In which direction will the equilibrium shift and what happens to the value of Keq
when the temperature of the system is increased?
Shift Keq
A. right increases
B. right decreases
C. left increases
D. left decreases
30. Consider the following equilibrium system: 2NO(g) + Cl2(g) ⇌ 2NOCl(g) + 25 kJ
In which direction will the equilibrium shift and what happens to the value of Keq when
NO is added?
Shift Keq
A. right increases
B. right constant
C. left increases
D. left constant
31. Consider the following equilibrium: 2COF2(g) ⇌ CO2(g) + CF4(g)
Initially, 0.32 M CO2 and 0.40 M CF4 are placed in a container. At equilibrium, it is
found that the [COF2] is 0.16 M.
What is the value of Keq?
A. 0.026
B. 1.5
C. 9.3
D. 3.0
32. Consider the following equilibrium: CCl4(g) ⇌ C(s) + Cl2(g)
Initially, 0.62 mol CCl4 was placed in a 2.0L container.
At equilibrium, [Cl2] = 0.060 M. Which of the following is the value of Keq?
A. 0.00039
B. 0.24
C. 0.014
D. 0.78
33. Consider the following equilibrium: 2COF2(g) ⇌ CO2(g) + CF4(g) Initially, 0.16 M
CO2 and 0.20 M CF4 are placed in a container. At equilibrium, it
is found that the [COF2] is 0.080 M.
What is the value of Keq?
A. 0.12
B. 1.5
C. 8.0
D. 3.0
You might also like
- A. Strong Acid, Weak Base, Salt: Final Examination Subject: General Chemistry A. Subject Code: 604001No ratings yetA. Strong Acid, Weak Base, Salt: Final Examination Subject: General Chemistry A. Subject Code: 6040016 pages
- 03 Solubility Study Guide - Multiple ChoiceNo ratings yet03 Solubility Study Guide - Multiple Choice24 pages
- EDUC 3136 A TeST 1 Reaction Kinetics 2023 PDFNo ratings yetEDUC 3136 A TeST 1 Reaction Kinetics 2023 PDF11 pages
- Chelsea Clio Budiman - Equibrium Introductory Conceptual Question100% (1)Chelsea Clio Budiman - Equibrium Introductory Conceptual Question4 pages
- Chapter 4 & 5 AP Notes Chemical Reactions & Stoichiometry NOTESNo ratings yetChapter 4 & 5 AP Notes Chemical Reactions & Stoichiometry NOTES20 pages
- Chemical Equilibrium Unit Review (Chemistry 12) I. Multiple Choice (60 Marks)100% (1)Chemical Equilibrium Unit Review (Chemistry 12) I. Multiple Choice (60 Marks)20 pages
- AP Chemistry Study Guide: Chapter 14: Acids and Bases and Chapter 15, 16.1 and 21.3: Aqueous and Acid-Base EquilibriaNo ratings yetAP Chemistry Study Guide: Chapter 14: Acids and Bases and Chapter 15, 16.1 and 21.3: Aqueous and Acid-Base Equilibria8 pages
- AP Chem Thermochemistry Multiple Choice 2018-01-09No ratings yetAP Chem Thermochemistry Multiple Choice 2018-01-0917 pages
- CHEM 201 Self Quiz - 1 (Experimental Errors/Statistical Analysis)100% (1)CHEM 201 Self Quiz - 1 (Experimental Errors/Statistical Analysis)2 pages
- Chapter 10. Practice Problems Part I. True or FalseNo ratings yetChapter 10. Practice Problems Part I. True or False1 page
- AP Chapter 13 MC Practice Questions With MC AnswersNo ratings yetAP Chapter 13 MC Practice Questions With MC Answers9 pages
- Managing Change: Self-Assessment Questions and AnswersNo ratings yetManaging Change: Self-Assessment Questions and Answers7 pages
- Angelic Dominion Lost: "Have You Come To Torment Us Before Our Time?"No ratings yetAngelic Dominion Lost: "Have You Come To Torment Us Before Our Time?"25 pages
- Noah The Real Story: God Always Extends Chance After Chance, Opportunity After OpportunityNo ratings yetNoah The Real Story: God Always Extends Chance After Chance, Opportunity After Opportunity57 pages
- The Sins of The Mouth - Creflo Dollars PDF100% (1)The Sins of The Mouth - Creflo Dollars PDF36 pages
- Production Chemicals Compatibility Against Fluid100% (1)Production Chemicals Compatibility Against Fluid53 pages
- Isc Class 12 March20 Chemistry Question Paper Solutions 2023No ratings yetIsc Class 12 March20 Chemistry Question Paper Solutions 202314 pages
- Thermodynamics of The Dissolution of BoraxNo ratings yetThermodynamics of The Dissolution of Borax7 pages
- Thermodynamics of Fluid-Phase Equilibria For Standard ChemicNo ratings yetThermodynamics of Fluid-Phase Equilibria For Standard Chemic23 pages
- 2023phenolic Compounds and Antioxidants Activity of Banana Peel Extracts - Testing and Optimization of Enzyme-Assisted ConditionsNo ratings yet2023phenolic Compounds and Antioxidants Activity of Banana Peel Extracts - Testing and Optimization of Enzyme-Assisted Conditions7 pages
- Ionic Equilibrium: Practice Sheet - Arjuna NEET 2024No ratings yetIonic Equilibrium: Practice Sheet - Arjuna NEET 20244 pages
- Jedreiergeo-Com Copper Article1 Chemistry of Copper Leaching-HTML NxwycNo ratings yetJedreiergeo-Com Copper Article1 Chemistry of Copper Leaching-HTML Nxwyc14 pages
- General, Organic, and Biochemistry 11th Edition Katherine J. Denniston All Chapter Instant Download100% (4)General, Organic, and Biochemistry 11th Edition Katherine J. Denniston All Chapter Instant Download47 pages
- Biopharmaceutics Classification System An Industrial ExperienceNo ratings yetBiopharmaceutics Classification System An Industrial Experience10 pages
- Fruit Weight, Firmness and Soluble Solids Content During Ripening of Karešova Cv. Sweet CherryNo ratings yetFruit Weight, Firmness and Soluble Solids Content During Ripening of Karešova Cv. Sweet Cherry7 pages
- Chemistry Coursework Gcse Rates of Reaction100% (2)Chemistry Coursework Gcse Rates of Reaction8 pages