CHEM 102 Winter 23 Final Exam (C)

On the answer sheet (scantron) write your last name, first name initial (FI), middle name initial (MI) (if
applicable), Drexel ID number, and lab section number. Choose the best (most correct) answer for each
question and fill in the corresponding bubbles for all 51 questions. Look at the example of a correctly filled
bubble at the top of your scantron sheet. Do NOT go past the frame of the bubbles. DO NOT CROSS
OUT bubbles. DO NOT MARK/WRITE anything else on the scantron sheet.

Potentially useful data:

− b ± b2 − 4 a c
x= 1 atm = 760 torr = 760 mm Hg
2a
[A]t = – kt + [A]o ΔG° = ΔH° – T ΔS°
ln[A]t = – kt + ln[A]o ΔG = ΔG° + RT lnQ
1/[A]t = kt +1/[A]o ΔG° = – RT lnK
First order half-life: t1/2 = ln2 / k ΔG = – nFE

E = E° − 0.0592 log Q
pH = pK a + log
[base] n
[acid ]
-1 -1
R = 8.314 J mol K F = 96500 C/mol = 96500 J/mol V
q = mcΔT 1 C = 1 J /V
-14
Kw = 10 at at 25 °C

1. Please choose the letter “C” as your answer for this question.

2. Which statement is FALSE about the compound below?

a) The addition of two hydrogen atoms to this compound would convert it into an alkyne.
b) This compound can be used as a monomer for addition polymerization.
c) This compound is a hydrocarbon.
d) There are two possible, distinct 3-D orientations of the hydrogen atoms around the C=C bond.
e) Methylcyclohexane is a structural isomer of this compound.

+ –4
3. Estimate the [H3O ] in a buffer that consists of 0.30 M HCOOH (Ka = 1.7 × 10 ) and 0.20 M HCOONa.
–4
a) 2.6 × 10 M
–4
b) 1.1 × 10 M
–4
c) 4.3 × 10 M
–5
d) 6.7 × 10 M
–5
e) 7.6 × 10 M
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4. How many hydrogen atoms would be present in the molecule shown below?
F

a) 10
b) 9
c) 5
d) 12
e) 7

– + –2
5. Estimate the [OH ] for a solution in which [H3O ] = 8.23 × 10 M at 25 °C. Is the solution acidic or basic?
-5
a) > 10 M, basic
-6
b) 1.22 × 10 M, basic
-12
c) 8.23 × 10 M, acidic
-16
d) 8.23 × 10 M, basic
-13
e) 1.22 × 10 M, acidic

6. The reaction rate generally decreases when _________ .

a) the surface contact area of reactants decreases
b) the activation energy increases
c) both a) and b)
d) the temperature of reaction increases
e) both b) and d)

7. Which compound below would be expected to behave as the weakest acid when put in water?
a) HOCl
b) HOBr
c) HOI
d) All of the above acids are very strong, since they contain O atoms.
e) All of the above acids have the same strength, since they have similar molecular formulas.

8. Which substance exhibits only London (dispersion) forces among its molecules?
a) HF
b) SiCl4
c) PF3
d) CH3-CH3
e) both b) and d)
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9. What is the minimum volume (in mL) of 0.55 M Mg(OH)2 required to neutralize 3.00 L of 0.15 M HCl?
2
a) 8.2 × 10 mL
2
b) 4.1 × 10 mL
-3
c) 1.8 × 10 mL
-2
d) 2.2 × 10 mL
3
e) 4.4 × 10 mL

10. Determine the molar solubility of Al(OH)3 in a solution containing 0.05 M AlCl3.
-33
Ksp for Al(OH)3 is 1.3 × 10 .
-9
a) 2.6 × 10 M
-31
b) 5.2 × 10 M
-35
c) 6.5 × 10 M
-29
d) 1.04 × 10 M
-12
e) 9.9 × 10 M

11. Which one of the compounds below would exist as geometric isomers?

a) CH3-CH2-CH2-CH3
b) CH2=CH-CH2-CH3
c) CH3-C≡C-CH3
d) CH3-CH=CH-CH3
e) both b) and d)

12. Calculate the oxidation number for S in K2S2O7.

a) +6
b) +4
c) +7
d) -4
e) +2

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 2+
13. A solution of KBr is added dropwise to a solution in which [Pb ] = 0.0158 M. When the concentration of
- -6
Br ions exceeds ________ , PbBr2 (Ksp = 6.6 × 10 ) will precipitate. Neglect volume changes.
–5
a) 5.4 × 10 M
–8
b) 2.7 × 10 M
–2
c) 2.0 × 10 M
–3
d) 2.6 × 10 M
–4
e) 1.1 × 10 M

14. A solution containing more than the equilibrium amount of dissolved solute is called ______ .
a) unsaturated
b) supersaturated
c) concentrated
d) saturated
e) None of the above.

15. How many structural (constitutional) isomers can be written for C5H10, excluding the cyclic structures?

a) 1
b) 2
c) 5
d) 4
e) 3

16. When compared to nonmetals, metals are typically classified as ______ .

a) being stronger oxidizing agents
b) having higher standard reduction potentials
c) being stronger reducing agents
d) being weaker reducing agents
e) being easily reduced

o o
17. Use the data below to calculate the change in entropy, ΔS rxn, for the following reaction at 25 C:
4 Cr (s) + 3 O2 (g) → 2 Cr2O3 (s)
Substance: Cr (s) O2 (g) Cr2O3 (s)
S°(J/K•mol): 23.77 205.138 81.2

a) 548.1 J/K
b) –147.7 J/K
c) 147.7 J/K
d) 310.1 J/K
e) - 548.1 J/K
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18. Which of the following processes is characterized by a negative value of ∆G?
a) the transfer of heat from a cold object to a warmer one
o
b) the freezing of water at 5 C
c) a balloon inflating when covered with cold water
o
d) the boiling of water at 200 C
e) None of the above.

19. Consider the overall reaction below for an electrochemical cell with Ecell = 2.350 V at 200.0 °C. ∆G at this
temperature is ____ and the cell is ________ .

2 Na (l) + FeCl2 (s) → 2 NaCl (s) + Fe (s)

a) – 453.5 kJ; spontaneous
b) + 453.5 kJ; non-spontaneous
c) – 226.8 kJ; non-spontaneous
d) + 226.8 kJ; spontaneous
e) – 453.5 kJ; at redox equilibrium

20. Which substance below has the highest vapor pressure at room temperature?

a) CH3-CH2-OH (l)
b) H2O (l)
c) CH3-O-CH3 (l)
d) CH3-CH2-CH2-CH2-OH (l)
e) CH3-COOH (l)

o
21. The cell shown below has E cell = + 1.41 V.
3+ 2+
Al(s) | Al (aq) || Ni (aq) | Ni(s)
3+ 2+
The concentration of Al (aq) is 0.050 M and the concentration of Ni (aq) is 2.0 M.
o
Estimate the cell potential at 25 C.

a) +1.34 V
b) +1.38 V
c) -1.41 V
d) +1.44 V
e) +1.48 V

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Use the phase diagram below to answer questions 22 and 23:

(atm)

o
( C)

22. Each point in the phase diagram above represents a different combination of temperature and pressure
values for a substance. Which action is most likely to produce the vaporization of the substance?
a) increasing the temperature of the substance at point 6
b) increasing the pressure of the substance at point 5
c) decreasing the pressure of the substance at point 4
d) decreasing the pressure of the substance at point 2
e) decreasing the temperature of the substance at point 1

23. Choose the true statement.

a) The triple point would be at a higher temperature than point 4.
b) The intersection of the three curves shows the critical point.
c) The 2 to 5 transition would be exothermic.
d) The 3 to 2 transition would increase the substance entropy.
e) The 6 to 1 transition would be endothermic.

24. Kinetics studies for the reaction below showed that the reaction became three times faster when the
concentration of B was tripled at the same temperature. The reaction is ______ order in B.
A+B → P
a) one-half
b) third
c) zero
d) second
e) first

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25. Which of the following corresponds to the lowest point in an energy diagram for an endothermic chemical
reaction?
a) more info is needed
b) products
c) transition state
d) reaction enthalpy
e) reactants

26. What value could indicate a pH at the equivalence point for a weak acid – strong base titration?
a) 6.8
b) 7.0
c) 5.5
d) 12
e) 8.2

27. Consider the titration of acetic acid, CH3COOH, with sodium hydroxide, NaOH, that you ran in the lab.
What happened halfway to the equivalence point?

a) pH = pKa
b) Half the acid has been converted to its conjugate base.
c) both a) and b)
d) The end point equals the equivalence point.
e) pH/2 = pKa

28. Which of the following is NOT conserved in a chemical reaction?

a) matter
b) entropy
c) energy
d) the identity of the atoms
e) total number of electrons

29. What are the strongest attractive solute-solvent interactions when H2S is dissolved in water?

a) ion-dipole forces
b) covalent bonds
c) dipole-dipole forces
d) London (dispersion) forces
e) hydrogen bonding

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30. Which of the following factors CANNOT affect the rate of a reaction?
a) the presence of a catalyst
b) the chemical reactivity of reactants and products
c) the concentrations of the reactants
d) the equilibrium constant
e) the temperature at which the reaction occurs

31. Sulfur dioxide combines with oxygen to form sulfur trioxide in an exothermic reaction, according to the
chemical equation below. Which change (or changes) will shift the equilibrium towards reactants?
2 SO2 (g) + O2 (g) ⇌ 2 SO3 (g)
a) raising the temperature
b) increasing the pressure
c) adding O2 (g)
d) compressing the mixture
e) both a) and b)

32. Consider the following reaction:

2A + B + 2C → P
If the reaction is zero order with respect to A, second order with respect to B, and first order with respect to
C, what are the units of measure for the rate constant? Assume the time measured in seconds.
-3 -1
a) M s
-1 -1
b) M s
-1
c) s
-2 -1
d) M s
-1
e) M s

-2 o
33. The equilibrium shown by the chemical equation below is characterized by Kp = 7.52 × 10 at 480 C.
2 H2O (g) + 2 Cl2 (g) 4 HCl + O2 (g)
Estimate the value of Kp for the reaction shown by the following equation, at the same temperature.
2 HCl (g) + 1/2 O2 (g) H2O (g) + Cl2 (g)
a) 0.274
-3
b) 5.66 × 10
c) 13.3
-2
d) - 3.76 × 10
e) 3.65

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34. In which of the following would Cd(OH)2 dissolve the least?

a) 0.2 M HCl
b) pure water
c) 0.1 M H2SO4
d) 0.3 M NaOH
-9
e) 0.2 M HClO (Ka = 2.8 × 10 )

35. Which is the correct equilibrium constant expression for the following reaction?

FeO (s) + H2 (g) Fe (s) + H2O (g)

a) Kc = [Fe][H2O] / [FeO]
b) Kc = [H2O] / [H2]
c) Kc = [FeO][H2] / [Fe][H2O]
d) Kc = [Fe][H2O] / [FeO][H2]
e) Kc = [H2] / [H2O]

36. What is the correct equation for the overall reaction rate of ammonia formation expressed as a function of
the hydrogen molar concentration?
N2 (g) + 3 H2 (g) → 2 NH3 (g)

a) rate = + 3Δ[H2]/Δt
b) rate = - 3Δ[H2]/Δt
c) rate = - 1/3 Δ[H2]/Δt
d) rate = + 1/3 Δ[H2]/Δt
e) rate = - Δ[H2]/Δt

37. In which of the following aqueous solutions does the weak acid exhibit the highest percent ionization?
-2
a) 0.01 M H2SO3 (Ka =1.6 × 10 )
+ -10
b) 0.01 M NH4 (Ka =5.6 × 10 )
-4
c) 0.01 M HF (Ka =6.8 × 10 )
-5
d) 0.01 M CH3COOH (Ka =1.8 × 10 )
e) Since the molar concentration is the same, all given acids will exhibit the same percent ionization.

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38. Which of the following shows a reaction that is spontaneous at low temperatures and non-spontaneous at
high temperatures?

a) ∆H > 0, ∆S < 0
b) ∆H < 0, ∆S < 0
c) ∆H > 0, ∆S = 0
d) ∆H < 0, ∆S > 0
e) ∆H > 0, ∆S > 0

39. Estimate the half-life (in minutes) for the zero-order reaction A2 → 2 A. The initial molar concentration of
-2 -1
A2 is 1.48 mol/L and the rate constant is 1.98 × 10 M min .
a) 18.7 min
b) 37.4 min
c) 35.0 min
d) 23.5 min
e) 50.0 min

40. Which of the following chemical entities is amphoteric?

a) LiH
+
b) H3O
2–
c) SO3
–
d) HSO3
e) C

2
41. At 745 K, the reaction below has an equilibrium constant (Kc) of 5.00 × 10 .

H2 (g) + I2 (g)  2 HI (g)

If a mixture of 0.10 mol H2, 0.10 mol I2 and 0.50 mol HI is sealed in a 1.00 L flask and heated to 745 K,
what is the concentration of HI (g) when equilibrium is established?
a) 0.029 M
b) 0.64 M
c) 0.14 M
d) 0.071 M
e) 25 M

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42. Estimate the number of grams of NaHCO3 in 150.0 g of a NaHCO3(aq) solution that is 2.25% by mass.

a) 3.38 g
b) 66.7 g
c) 1.50 g
d) 225 g
e) 338 g

43. In the chemical equilibrium below,

– –
H2CO3 + F HCO3 + HF
– –
a) F and HCO3 are Brønsted-Lowry bases.
–
b) F is a Brønsted-Lowry base and H2CO3 is a Brønsted-Lowry acid.
–
c) H2CO3 is a base and HCO3 is its conjugate acid.
–
d) H2CO3 is an acid and F is its conjugate base.
e) both a) and b)

44. What would be best to use to make a buffer solution with a neutral pH?
a) an equimolar mixture of a strong acid and a strong base
b) an equimolar mixture of an extremely weak acid and an extremely strong base
c) a weak acid with a pKa near -7 and its conjugate base
-7
d) a weak acid with a Ka near 1.00 × 10 and its conjugate base
e) None of the above.

45. Nitric acid is a strong acid. What does that statement mean?
+ -
a) Aqueous solutions of HNO3 contain equal concentrations of H3O (aq) and HO (aq).
+ -
b) In aqueous solution, HNO3 basically dissociates completely to H3O (aq) and NO3 (aq).
c) Nitric acid exhibits a very low percent ionization when dissolved in water.
d) Nitric acid cannot be neutralized by a weak base.
e) Nitric acid is characterized by a large pKa value.

46. What mass of CuBr2 is needed to prepare 750 mL of 1.25 M CuBr2 (aq)?
a) 209 g
b) 938 g
c) 372 g
d) 134 g
e) The density of the solution is needed to determine.

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 + -8
47. Estimate the [H3O ] in a 0.265 M HClO solution (Ka of HClO is 2.9 × 10 ).
-10
a) 1.1 × 10 M
-9
b) 7.7 × 10 M
-5
c) 8.8 × 10 M
-4
d) 4.9 × 10 M
-6
e) 1.3 × 10 M

48. Which substance contains the oxidizing agent in the following redox reaction?
CuO (s) + H2 (g) → Cu (s) + H2O (l)
a) H2O
b) H2
c) Cu
d) CuO
e) None. This is not a redox reaction.

49. Consider the ionization steps of a triprotic acid in water. Which of the following mathematical relationships
is true?
a) pKa1 > pKa2 > pKa3
b) Ka1 > Ka2 > Ka3
c) Ka1 < Ka3 < Ka2
d) pKa1 ≈ pKa2 << pKa3
e) Ka1 = Ka2 = Ka3

50. If the reaction quotient is greater than the equilibrium constant, then a reversible process _______ .
a) will not proceed in either direction
b) has not yet started in the forward direction
c) has gone to 100% completion and reached equilibrium
d) will proceed toward products to reach equilibrium
e) will proceed toward reactants to reach equilibrium

51. Calculate the energy required to convert 25 g of ice at –15 °C to steam at 150 °C.
For water:
∆Hfus = 334 J/g; ∆Hvap = 2260 J/g; cice = 2.06 J/g °C; cwater = 4.184 J/g °C; csteam = 2.03 J/g °C
a) 2.54 kJ
b) 56.5 kJ
c) 78.6 kJ
d) 96.8 kJ
e) 8.35 kJ

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chem102w23_final exam C

Answer Section
MULTIPLE CHOICE

1. ANS: C PTS: 0
2. ANS: A PTS: 1
3. ANS: A PTS: 1
4. ANS: B PTS: 1
5. ANS: E PTS: 1
6. ANS: C PTS: 1
7. ANS: C PTS: 1
8. ANS: E PTS: 1
9. ANS: B PTS: 1
10. ANS: E PTS: 1
11. ANS: D PTS: 1
12. ANS: A PTS: 1
13. ANS: C PTS: 1
14. ANS: B PTS: 1
15. ANS: C PTS: 1
16. ANS: C PTS: 1
17. ANS: E PTS: 1
18. ANS: D PTS: 1
19. ANS: A PTS: 1
20. ANS: C PTS: 1
21. ANS: D PTS: 1
22. ANS: C PTS: 1
23. ANS: E PTS: 1
24. ANS: E PTS: 1
25. ANS: E PTS: 1
26. ANS: E PTS: 1
27. ANS: C PTS: 1
28. ANS: B PTS: 1
29. ANS: C PTS: 1
30. ANS: D PTS: 1
31. ANS: A PTS: 1
32. ANS: D PTS: 1
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33. ANS: E PTS: 1
34. ANS: D PTS: 1
35. ANS: B PTS: 1
36. ANS: C PTS: 1
37. ANS: A PTS: 1
38. ANS: B PTS: 1
39. ANS: B PTS: 1
40. ANS: D PTS: 1
41. ANS: B PTS: 1
42. ANS: A PTS: 1
43. ANS: E PTS: 1
44. ANS: D PTS: 1
45. ANS: B PTS: 1
46. ANS: A PTS: 1
47. ANS: C PTS: 1
48. ANS: D PTS: 1
49. ANS: B PTS: 1
50. ANS: E PTS: 1
51. ANS: C PTS: 1

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