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® Chemistry : Ionic Equilibrium

Pre-Medical

EXERCISE-I (Conceptual Questions) Build Up Your Understanding

INTRODUCTION 10. The number of milli equivalents of acid in 100 mL
of 0.5N HCl solution is:-
1. The formula weight of H2SO4 is 98. The weight
(1) 50 (2) 100
of the acid in 400mL of 0.1 M solution is:-
(3) 25 (4) 200
(1) 2.45 g (2) 3.92 g (3) 4.90 g (4) 9.8 g
IE0010
IE0001
11. If the molar concentration of PbI2 is
2. Normality of 2M sulphuric acid is:- –3 –1
(1) 2 N (2) 4N (3) N/2 (4) N/4 1.5 × 10 mol L , then the concentration of
–1
IE0002 iodide ions in g ion L is:-
–3 –3
+
(1) 3.0 × 10 (2) 6.0 × 10
3. If pH = 3.31, then find out [H ] (Approximately) –3 –6
(3) 0.3 × 10 (4) 0.6 × 10
–4 –4
(1) 3.39 × 10 M (2) 5 × 10 M IE0011
–3
M (4) 2 × 10–4 M

®
(3) 3.0 × 10
IE0003 OSTWALD'S DILUTION LAW

– –5 12. Order of dissociation of 0.1 N CH3COOH is :-

4. If [OH ] = 5.0 × 10 M then pH will be :-
–5
(1) 5 – log 5 (2) 9 + log 5 (Dissociation constant = 1 × 10 )
–5 –4 –3 –2
(3) log 5 – 5 (4) log 5 – 9 (1) 10 (2) 10 (3) 10 (4) 10
IE0004 IE0012

5. Basicity of H3PO3 and H3PO2 is respectivily :- 13. The degree of dissociation of acetic acid is given by
(1) 1 and 2 (2) 2 and 3 the expression α = 0.1 ×C (where C = concentration
–1

(3) 3 and 2 (4) 2 and 1 of the acid) What is the pH of the solution :-
IE0005 (1) 1 (2) 2 (3) 3 (4) 4
–3 IE0014
6. Find out pH of solution having 2 × 10 moles of
–
OH ions in 2 litre solution :- 14. Ostwald's dilution law is not applicable for strong
(1) pH = 3 (2) pH = 3 + log2 electrolytes because:-
(3) pH = 3 – log2 (4) pH = 11 (1) Strong electrolytes are completely ionised
IE0006 (2) Strong electrolytes are volatile
(3) Strong electrolytes are unstable
7. The pH of a soft drink is 3.82. The hydrogen ion (4) Strong electrolytes often contain metal ions
concentration will be:- IE0015
–2 –1 –4 –1
(1) 1.96 × 10 mol L (2) 1.6 × 10 mol L
–5
(3) 1.96 × 10 mol L
–1
(4) None of them 15. The degree of ionisation of a compound depends
NIE0367 upon :
(1) Size of the solute molecules
8. 8 g NaOH is dissolved in one litre of solution, the (2) Nature of the solute molecules
molarity of the solution is:- (3) Nature of the container taken
(1) 0.2 M (2) 0.4 M (4) The amount of current passed
(3) 0.02 M (4) 0.8 M IE0016
IE0008
–2
16. Find out Ka for 10 M HCN acid, having pOH
9. The amount of acetic acid present in 100 mL of is 10 :-
0.1M solution is :- (1) Ka = 10
–4
(2) Ka = 10
–2

(1) 0.30 g (2) 3.0 g –5

(3) Ka = 10 (4) None of them
(3) 0.60 g (4) None
IE0009 IE0017

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17. Which of the following will occur if a 1.0 M solution 25. At 25°C, the dissociation constant for pure water
of a weak acid is diluted to 0.01 M at constant is given by :-
14 –1 –14
temperature:- (1) (55.4 × 10 ) (2) 1 × 10
(1) Percentage ionisation will increase 1 × 10−14
+ (3) (4) None of these
(2) [H ] will decrease to 0.01M 18
(3) Ka will increase IE0026
(4) pH will decrease by 2 units 26. Ionic product of water is equal to :-
IE0018
(1) Dissociation constant of water × [H2O]
+
18. The pH of 0.15 M solution of HOCl (2) Dissociation constant of water × [H ]
+
(Ka = 9.6 × 10 ) is:-
–6 (3) Product of [H2O] and [H ]
– 2 +
(1) 4.42 (2) 2.92 (3) 3.42 (4) None (4) Product of [OH ] and [H ]
NIE0368 IE0027
+ –
19. The extent of ionisation increases (weak electrolytes) 27. Addition of H and OH ion's concentration in
(1) With the increase in concentration of solute pure water at 90°C is :-

®
–14 –12 –6 –7
(2) On decreasing the temp. of solution (1) 10 (2) 10 (3) 2 × 10 (4) 2 × 10
(3) On addition of excess of water to the solution IE0028
(4) On stirring the solution vigorously
IE0020 28. The units of ionic product of water (KW) are:-
–1 –1 –2 –2
–10
(1) mol L (2) mol L
20. If Ka of HCN = 4 × 10 , then the pH of –2 –1 2 –2
–1
(3) mol L (4) mol L
2.5 × 10 molar HCN (aq) is:- NIE0370
(1) 4.2 (2) 4.7 (3) 0.47 (4) 5.0
+ –6.7 –1
IE0021 29. At 90°C, pure water has [H3O ] =10 mol L
what is the value of KW at 90°C:-
21. The molarity of nitrous acid at which its pH –6 –12 –67 –13.4
–4 (1) 10 (2) 10 (3) 10 (4) 10
becomes 2.(Ka = 4.5 × 10 ) :-
IE0029
(1) 0.3333 (2) 0.4444
(3) 0.6666 (4) 0.2222 30. At 373 K, temp. the pH of pure H2O will be :-
IE0022 (1) < 7 (2) > 7
(3) = 7 (4) = 0
EXPLANATION OF WATER IE0030
22. Ionic product of water will increase, if we :- 31. Choose the correct relation:-
(1) Decrease the pressure pH + pOH
+ (1) =7 (2) pH + pOH = 14
(2) Add H 14
(3) Add OH
– (3) pOH = 14 + pH (4) pH = 14 + pOH
NIE0371
(4) Increase the temperature
IE0024 32. The common ion effect is shown by which of the
following sets of solutions :-
–7
23. For water at 25° C, 2 × 10 moles per litre is the (1) BaCl2 + Ba(NO3)2 (2) NaCl + HCl
correct answer for which one of the followoing (3) NH4OH + NH4Cl (4) None
+
(1) [H ] + [OH ]
–
(2) [H ]
+ 2
NIE0372
– 2 + –
(3) [OH ] (4) [H ] – [OH ] 33. Basic strength of NH4OH in presence of NH4Cl
IE0025 (1) Increases
(2) Remains unchanged
24. The pH of H2O at its boiling point :- (3) Decreases
(1) < 7 (2) > 7 (4) Sometimes increases or sometimes decreases
(3) 7 (4) 0 NIE0373
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34. Which of the following is a true statement : 41. What will be the pH of 1.0 M ammonium
(1) The ionisation constant and ionic product of –4 –5
formate solution, If Ka=1 × 10 acid Kb =1× 10 :-
water are same.
(2) Water is a strong electrolyte. (1) 6.5 (2) 7.5 (3) 8.0 (4) 9.0
(3) The value of ionic product of water is less IE0041
than that of its ionisation constant.
+
(4) At 298K, the number of H ions in a litre of 42. Which salt will not undergo hydrolysis :-
16
water is 6.023 × 10 . (1) KCl (2) Na2SO4
IE0033 (3) NaCl (4) All
35. If it is known that H2S is a weak acid and it is IE0042
+ –2
ionised into 2H and S . Then in this solution
– –
HCl is added so, pH becomes less, then what will 43. 
HCOO + H2O  HCOOH + OH is related:-
happen :-
–2 Kh
(1) Decrease in S ion concentration (1) h = Kh (2) h =
–2
C
(2) Concentration of S is not affected

®
Kh
–2
(3) Increase in S ion concentration (3) h = (4) Kh = hc
V
(4) It is not possible, to add HCl in solution
IE0044
NIE0374
44. The pH of aqueous solution of sodium acetate is
SALTS, TYPES OF SALT AND (1) 7 (2) Very low
CONJUGATE THEORY
(3) > 7 (4) < 7
36. Which of the following is not an acidic salt :- IE0045
(1) NaHSO4 (2) HCOONa
– o
(3) NaH2PO3 (4) None of them 45. If pKb for CN at 25 C is 4.7. The pH of 0.5M
IE0035 aqueous NaCN solution is :-
(1) 12 (2) 10 (3) 11.5 (4) 11
37. Which is a basic salt :–
IE0046
(1) PbS (2) PbCO3
(3) PbSO4 (4) 2PbCO3 Pb(OH)2 46. The highest pH value is of :-
IE0036 (1) 0.1 M NaCl (2) 0.1 M NH4Cl
38. The process of neutralisation invariably results in (3) 0.1 M CH3COONa (4) 0.1 M CH3COONH4
the production of :- IE0047
+
(1) H ions
(2) OH ions
— 47. pH of K2S solution is:-
+
(3) Both H and OH ions
— (1) 7 (2) Less than 7
(4) Molecules of water (3) More than 7 (4) 0
IE0037 IE0048

39. Which of the following is an acidic salt :- 48. For anionic hydrolysis, pH is given by:-
(1) Na2S (2) Na2SO3 1 1 1
(1) pH = pKW – pKb – logc
(3) NaHSO3 (4) Na2SO4 2 2 2
1 1 1
IE0038 (2) pH = pKW + pKa – pKb
2 2 2
SALT HYDROLYSIS 1 1 1
(3) pH = pKW + pKa + logc
40. At 90° C, the pH of 0.1M NaCl aqueous solution 2 2 2
is :- (4) None of above
(1) < 7 (2) > 7 (3) 7 (4) 0.1 IE0049
IE0040
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49. A weak acid reacts with strong base, ionisation SOLUBILITY & SOLUBILITY PRODUCT (Ksp)
–4
constant of weak acid is 10 . Find out equilibrium
constant for this reaction :- 55. If solubility of salts M2X, QY2 and PZ2 is equal,
–10 10 –9 9
(1) 10 (2) 10 (3) 10 (4) 10 then the relation between their Ksp will be :-
IE0050
(1) Ksp(M2X) > Ksp (QY2) > Ksp (PZ2)
—
50. Hydroxyl ion concentration [OH ] in the case of (2) Ksp(M2X) = Ksp (QY2) < Ksp (PZ2)
sodium acetate can be expressed as (where Ka is
(3) Ksp(M2X) > Ksp (QY2) = Ksp (PZ2)
dissociation constant of CH3COOH and C is the
concentration of sodium acetate):- (4) Ksp(M2X) = Ksp (QY2) = Ksp (PZ2)
– 1/2
(1) [OH ] = (CKw. Ka) IE0058
–
(2) [OH ] = C.Kw K a 56. The expression of solubility product of mercurous
1/2
–  C.K w  iodide is :-
(3) [OH ] =   + 2 – 2 ++ 2 – 2

®
 Ka  (1) [2 Hg ] × 2 [I ] (2) [Hg ] × [ 2I ]
– 2 2+ 2 – 2
–
(4) [OH ] = C. Ka. Kw. (3) [ Hg22+ ] × [I ] (4) [Hg ] × [I ]
IE0051 IE0059

51. Consider :- 57. At 25°C, the Ksp value of AgCl is 1.8 × 10 . If

–10

(a) FeCl3 in water - Basic –5 +

10 moles of Ag are added to solution then Ksp
(b) NH4Cl in water - Acidic will be :-
(c) Ammonium acetate in water - Acidic –15 –10
(1) 1.8 × 10 (2) 1.8 × 10
(d) Na2CO3 in water - Basic –5 +10
(3) 1.8 × 10 (4) 18 × 10
Which is/are not correctly matched:-
(1) b and d (2) b only IE0060
(3) a and c (4) d only
58. At 25°C, required volume of water, to dissolve
IE0052 –10
1g BaSO4 (Ksp = 1.1 × 10 ) will be (Molecular
52. Which of the following salts undergoes hydrolysis
weight of BaSO4 = 233) :-
in water:-
(1) 820 L. (2) 1 L.
(1) Na3PO4 (2) CH3COONa (3) 205 L. (4) 430 L.
(3) NaNO3 (4) Both of (1) and (2) IE0061
IE0053
+
59. Concentration of Ag ions in saturated solution
53. A salt 'X' is dissolved in water of pH = 7. The –4 –1
of Ag2CrO4 at 20°C is 1.5 × 10 mol L . At
resulting solution becomes alkaline in nature. The
salt is made up of:- 20°C, the solubility product of Ag2CrO4 is :-
(1) A strong acid and strong base (1) 3.3750 × 10
–12
(2) 1.6875 × 10
–10

(2) A strong acid and weak base –12 –11

(3) 1.68 × 10 (4) 1.6875 × 10
(3) A weak acid and weak base
(4) A weak acid and strong base IE0062
IE0054
60. How many grams of CaC2O4 will dissolve in
N
54. Degree of Hydrolysis of solution of KCN is distilled water to make one litre saturated solution?
100 –9 2 –2
solubility product of CaC2O4 is 2.5 × 10 mol L
(Given Ka = 1.4 × 10 )
–9

and its molecular weight is 128.

(1) 2.7 × 10 (2) 2.7 × 10
–3 –2

(1) 0.0064 g (2) 0.0128 g

(3) 2.7 × 10 (4) 2.7 × 10
–4 –5

(3) 0.0032 g (4) 0.0640 g

NIE0375 NIE0376
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2–
61. If the concentration of CrO4 ion in a saturated APPLICATION OF SOLUBILITY PRODUCT (Ksp)
–4
solution of silver chromate will be 2 × 10 M, 68. At 30°C, In which of the one litre solution, the
solubility product of silver chromate will be - –12
–8 –12
solubility of Ag2CO3 (solubility product = 8 × 10 )
(1) 4 x 10 (2) 8 x 10
–12 –12
will be maximum :-
(3) 32 x 10 (4) 6 x 10
(1) 0.05 M Na2CO3 (2) Pure water
IE0064
(3) 0.05 M AgNO3 (4) 0.05 M NH3
62. If the solubility of AgCl (formula mass=143) in
NIE0378
water at 25°C is 1.43 ×10
–4
g/100 mL of
69. Solubility of AgBr will be minimum in :-
solution then the value of Ksp will be :–
(1) Pure water (2) 0.1 M CaBr2
(1) 1 × 10 (2) 2 × 10
–5 –5

(3) 0.1 M NaBr (4) 0.1 M AgNO3

(3) 1 × 10 (4) 2 × 10
–10 –10

IE0072
IE0065
70. In which of the following, the solution of AgSCN

®
63. If the salts M2X, QY2 and PZ3 have the same
will be unsaturated :-
solubilities, their Ksp values are related as - (S < 1) + – + –
(1) [Ag ] [SCN ] = Ksp (2) [Ag ] × [SCN ] < Ksp
(1) Ksp (M2X) = Ksp (QY2) < Ksp (PZ3) + – + – 2
(3) [Ag ] × [SCN ] > Ksp (4) [Ag ] [SCN ] < Ksp
(2) Ksp (M2X) > Ksp (QY2) = Ksp (PZ3)
IE0073
(3) Ksp (M2X) = Ksp (QY2) > Ksp (PZ3)
(4) Ksp (M2X) > Ksp (QY2) > Ksp (PZ3) 71. If 's' and 'S' are respectively solubility and solubility
product of a sparingly soluble binary electrolyte
NIE0377
then :–
2
64. The solubility product of As2S3 is given by the (1) s = S (2) s = S
expression :- 1/2 1
3+ –2 3+ 1 –2 1 (3) s = S (4) s = S
(1) Ksp = [As ] × [S ] (2) Ksp = [As ] [S ] 2
(3) Ksp = [As ] [S ]
3+ 3 –2 2
(4) Ksp = [As ] [S ]
3+ 2 –2 3
IE0074
IE0067 72. The solubility product of CuS , Ag2S and HgS
–37 –44 –54
65. If the solubility of PbBr2 is 'S' g molecules per are 10 , 10 and 10 respectively. The
litre, considering 100% ionisation its solubility solubility of these sulphides will be in the order
product is :- (1) HgS > Ag2S > CuS (2) Ag2S > HgS > CuS
(1) 2S
3
(2) 4S
2
(3) 4S
3
(4) 2S
4
(3) CuS > Ag2S > HgS (4) Ag2S > CuS > HgS
IE0068 IE0075

66. If the solubility of lithium sodium hexeafluoro 73. If the maximum concentration of PbCl2 in water
–1 is 0.01 M at 298 K, Its maximum concentration
aluminate Li3Na3(AlF6)2 is 'S' mol L . Its solubility
in 0.1 M NaCl will be:-
product is equal to :- –3 –4
8 3 (1) 4 × 10 M (2) 0.4 × 10 M
(1) S (2) 12 S –2 –4
3 8
(3) 4 × 10 M (4) 4 × 10 M
(3) 18 S (4) 2916 S IE0076
IE0069 +
74. M2SO4 (M is a monovalent metal ion) has a Ksp
67. One litre of saturated solution of CaCO3 is of 1.2 × 10
–5
at 298 K. The maximum
evaporated to dryness, then 7.0 g of residue is +
concentration of M ion that could be attained in
left. The solubility product for CaCO3 is:- a saturated solution of this solid at 298 K is :-
–3 –5 –3 –2
(1) 4.9 × 10 (2) 4.9 × 10 (1) 3.46 × 10 M (2) 2.89 × 10 M
–9 –7 –3 –3
(3) 4.9 × 10 (4) 4.9 × 10 (3) 2.8 × 10 M (4) 7.0 × 10 M
IE0070 IE0077

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75. Which of the following has maximum solubility 82. The solubility product constant Ksp of Mg(OH)2 is
(Ksp value is given in brackets) :- –12
9.0 × 10 . If a solution is 0.010 M with respect
–54 –8
(1) HgS (1.6 × 10 ) (2) PbSO4 (1.3 × 10 ) 2+
–26 –10
to Mg ion, what is the maximum hydroxide ion
(3) ZnS (7.0 × 10 ) (4) AgCl (1.7 × 10 ) concentration which could be present without
IE0078
causing the precipitation of Mg(OH)2 :-
76. Maximum soluble is :- (Ksp is given) –7 –7
–36 –28 (1) 1.5 × 10 M (2) 3.0 × 10 M
(1) CuS (8.5 × 10 ) (2) CdS (3.6 × 10 ) –5 –5
–28 –10 (3) 1.5 × 10 M (4) 3.0 × 10 M
(3) ZnS (1.2 × 10 ) (4) MnS (1.4 × 10 )
IE0079 IE0089
77. In which of the following, the solubility of AgCl will
83. When HCl gas is passed through a saturated solution
be maximum :-
of common salt, pure NaCl is precipitated because:-
(1) 0.1 M AgNO3 (2) Water
(3) 0.1 M NaCl (4) 0.1 M KCl (1) The impurities dissolve in HCl
IE0080 (2) HCl is slightly soluble in water

®
+ –
78. The solubility products of three sparingly soluble (3) The ionic product [Na ] × [Cl ] exceeds the
salts are given below : solubility product of NaCl
No. Formula Solubility product (4) The solubility product of NaCl is lowered by
–20
1 PQ 4.0 × 10 –
Cl from aq. HCl
–14
2 PQ2 3.2 × 10 IE0090
–35
3 PQ3 2.7 × 10
pH
The correct order of decreasing molar solublity is:-
–
(1) 1, 2, 3 (2) 2, 1, 3 84. Find out (OH ) concentration in pH = 3.28 solution
(3) 3, 2, 1 (4) 2, 3, 1 (1) 5.3 × 10
–4
(2) 5.3 × 10
–10

IE0081 –10 –11

(3) 1.8 × 10 (4) 1.8 × 10
79. If the solubility product of AgBrO3 and Ag2SO4
–5 –5 NIE0379
are 5.5 × 10 and 2 × 10 respectively, the
85. 0.001 N KOH solution has the pH :-
relationship between the solubilities of these can –1
be correctly represented as:- (1) 10 (2) 3
(1) s AgBrO3 > s Ag2SO4 (2) s AgBrO3 = s Ag2SO4 (3) 11 (4) 2
(3) s AgBrO3 < s Ag2SO4 (4) None of the above NIE0380
IE0083 86. Given :-
80. Solubility product of Mg(OH)2 is 1 × 10 . At what
–11 (a) 0.005 M H2SO4 (b) 0.1 M Na2SO4
–2
pH, precipitation of Mg(OH)2 will begin from 0.1 M (c) 10 M NaOH (d) 0.01 M HCl
2+
Mg solution :- Choose the correct code having same pH :-
(1) 9 (2) 5 (3) 3 (4) 7 (1) a, c, d (2) b, d
IE0085 (3) a, d (4) a, c
+2 IE0101
81. A solution, containing 0.01 M Zn and 0.01 M
2+ –2 87. If 100 mL of pH = 3 and 400 mL of pH = 3 is
Cu is saturated by passing H2S gas. The S
–21
concentration is 8.1 × 10 M, Ksp for ZnS and mixed, what will be the pH of the mixture
–22 –36
CuS are 3.0 × 10 and 8.0 × 10 respectively. (1) 3.2 (2) 3.0 (3) 3.5 (4) 2.8
Which of the following will occur in the solution:- IE0105
–6
(1) ZnS will precipitate 88. 10 M HCl is diluted to 100 times. Its pH is :-
(2) CuS will precipitate (1) 6.0 (2) 8.0 (3) 6.95 (4) 9.5
(3) Both ZnS and CuS will precipitate IE0106
2+ 2+
(4) Both Zn and Cu will remain in the solution 89. pH of 0.001M acetic acid would be :-
IE0086 (1) 2 (2) > 3 (3) 7 (4) 14
IE0107

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90. At 90°C, the pH of 0.001M KOH solution will be 98. The pOH of beer is 10.0. The hydrogen ion
(1) 3 (2) 11 (3) 5 (4) 9 concentration will be :–
IE0108 –10 Kw Kw –4
(a) 10 (b) −10
(c) (d) 10
91. The pH of solution is increased from 3 to 6. Its 10 10−8
+ (1) a, d (2) b, c
H ion concentration will be :-
(3) a, b, c (4) None
(1) Reduced to half IE0115
(2) Doubled
(3) Reduced by 1000 times 99. An aqueous solution whose pH = 0 is :-
(4) Increased by 1000 times (1) Basic (2) Acidic
IE0109 (3) Neutral (4) Amphoteric
IE0116
92. A solution has pOH equal to 13 at 298 K. The –10
100. The pH of a 10 M NaOH solution is nearest to:-
solution will be :-
(1) 10 (2) 7 (3) 4 (4) – 10
(1) Highly acidic
NIE0383

®
(2) Highly basic
(3) Moderately basic 101. The pH of the solution produced when an
(4) Unpredictable aqueous solution of strong acid pH 5 is mixed
IE0110 with equal volume of an aqueous solution of
strong acid of pH 3 is :-
93. The pH of a solution is defined by the equation:- (1) 3.3 (2) 3.5 (3) 4.5 (4) 4.0
(1) pH = – log [H3O ]
+
NIE0384
1 102. The pH of a 0.02 M ammonia solution which is
(2) pH = log
[H3 O + ]
5% ionised will be :-
+ –pH
(3) [H ] = 10 (1) 2 (2) 11 (3) 5 (4) 7
(4) All IE0119
NIE0381
103. Pure water is kept in a vessel and it remains
94. The pH of the solution containing 10 mL of a exposed to atmospheric CO2 which is absorbed.
0.1M NaOH and 10 mL of 0.05M H2SO4 would be Then the pH will be :-
(1) Greater than 7
(1) Zero (2) 1 (3) >7 (4) 7
(2) Less than 7
IE0111 (3) 7
(4) Depends on ionic product of water
95. In a solution of pH = 5, more acid is added in NIE0385
order to make the pH = 2. The increase in
–1
hydrogen ion concentration is:- 104. pH of 10 M formic acid is:-
(1) 100 times (2) 1000 times (1) 1 (2) > 1 (3) < 1 (4) 13
(3) 3 times (4) 5 times NIE0386
IE0113
N
–3 105. For H SO , pH value is :-
96. Calculate the pH of 4 × 10 M, Y(OH)2 solution 10 2 4
assuming the first dissociation to be 100% and (1) 1 (2) 0.586 (3) 0.856 (4) None
second dissociation to be 50%:- IE0120
(1) 11.78 (2) 9.9 (3) 2.5 (4) 2.22
–9
NIE0382 106. An aqueous solution of HCl is 10 M HCl. The
pH of the solution should be:-
97. The hydrogen ion concentration in a given
–4
(1) 9 (2) Between 6 and 7
solution is 6 × 10 M. Its pH will be :-
(3) 7 (4) Unpredictable
(1) 6 (2) 3.22 (3) 4 (4) 2
IE0121
IE0114
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107. H2X is a dibasic acid which dissociates completely BUFFER SOLUTIONS
in water. Which one of the following is the 114. In a buffer solution the ratio of concentration of
molarity of an aqueous solution of this acid which and NH4OH is 1 : 1 when it changes to
has a pH of 1 :- 2 : 1, what will be the value of pH of buffer :-
(1) 0.1 (2) 0.05 (1) Increase
(3) 0.2 (4) 0.5 (2) Decrease
NIE0387 (3) No effect
(4) N.O.T.
IE0131
108. 8 g NaOH and 4.9 g H2SO4 are present in one
115. In a mixture of weak acid and its salt, the ratio of
litre of the solution. What is its pH
concentration of acid to salt is increased ten-fold.
(1) 1 (2) 13 (3) 12 (4) 2 The pH of the solution :-
IE0124 (1) Decreases by one
(2) Increases by one-tenth
109. Calculate pH of a solution whose 100 mL (3) Increases by one

®
contains 0.2 g NaOH dissolved in it :- (4) Increases ten-fold
(1) 10.699 (2) 11.699 IE0134
(3) 12.699 (4) 13.699 116. pKb for NH4OH at certain temperature is 4.74.
IE0125 The pH of basic buffer containing equimolar
concentration of NH4OH and NH4Cl will be:-
110. What is the quantity of NaOH present in 250 cc (1) 7.74 (2) 4.74
of the solution, so that it gives a pH = 13 :- (3) 2.37 (4) 9.26
–13 –1
(1) 10 g (2) 10 g (3) 1.0 g (4) 4.0 g IE0135
IE0127
117. The buffer solution play an important role in :-
111. 0.001 mol of the strong electrolyte M(OH)2 has (1) Increasing the pH value
been dissolved to make a 20 mL of its saturated (2) Decreasing the pH value
–14
solution. Its pH will be : - [Kw = 1 × 10 ] (3) Keeping the pH constant
(1) 13 (2) 3.3 (3) 11 (4) 9.8 (4) Solution will be neutral
IE0128 IE0139
–10
112. Choose the wrong statement :- 118. Ka for HCN is 5 × 10 at 25°C. For maintaining a
(1) For a neutral solution : [H ] = [OH–] =
+
Kw constant pH of 9, the volume of 5M KCN solution
+ required to be added to 10mL of 2M HCN
(2) For an acidic solution : [H ] > Kw and
solution is-
[OH–] < Kw (1) 4 mL (2) 7.95 mL
+ (3) 2 mL (4) 9.3 mL
(3) For a basic solution : [H ] < Kw and
IE0140
–
[OH ] > Kw
119. Buffering action of a mixture of CH3COOH and
(4) For a neutral solution at all temperatures :
[H ] = [OH–] = 10 M
+ –7 CH3COONa is maximum when the ratio of salt
IE0129 to acid is equal to -
(1) 1.0 (2) 100.0
113. The pH of 0.1 M solution of the following salts (3) 10.0 (4) 0.1
increases in order :- IE0141
(1) NaCl < NH4Cl < NaCN < HCl 120. A basic - buffer will obey the equation
(2) NaCN < NH4Cl < NaCl < HCl pOH - pKb = 1 only under condition:-
(1) [Conjugate acid] : [base] = 1 : 10
(3) HCl < NaCl < NaCN < NH4Cl
(2) [Conjugate acid] = [base]
(4) HCl < NH4Cl < NaCl < NaCN (3) [Conjugate acid] : [base] = 10 : 1
(4) N.O.T
IE0130 IE0144

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121. A certain acidic buffer solution contains equal 128. Half of the formic acid solution is neutralised by
– –
concentration of X and HX. The Kb for X is addition of a KOH solution to it. If
–10 –4
10 . The pH of the buffer is :- Ka (HCOOH) = 2 × 10 then pH of the solution
(1) 4 (2) 7 (3) 10 (4) 14 is : (log 2 = 0.3010)
IE0149 (1) 3.6990 (2) 10.3010
122. When 1.0 mL of dil. HCl acid is added to 100 mL (3) 3.85 (4) 4.3010
of a buffer solution of pH 4.0. The pH of the solution IE0157
(1) Becomes 7
(2) Does not change 129. A solution contains 0.2M NH4OH and 0.2M NH4Cl.
(3) Becomes 2 If 1.0 mL of 0.001 M HCl is added to it. What
(4) Becomes 10
will be the [OH–] of the resulting solution
IE0150 –5
[Kb = 2 × 10 ] :-
123. The pH of blood is maintained by CO2 and H2CO3 (1) 2 × 10
–5
(2) 5 × 10
–10

in the body and chemical constituents of blood. –3

(3) 2 × 10 (4) None of these
This phenomenon is called :-

®
(1) Colloidal IE0158
(2) Buffer action 130. Henderson equation pH – pK a = 1 will be
(3) Acidity
applicable to an acidic buffer when :-
(4) Salt balance
(1) [Acid] = [Conjugate base]
IE0151
(2) [Acid] × 10 = [Conjugate base]
124. Which of the following solutions does not act as (3) [Acid] = [Conjugate base] × 10
buffer :– (4) None of these
(1) H3PO4 + NaH2PO4 IE0159
(2) NaHCO3 + H2CO3 131. 0.05 M ammonium hydroxide solution is dissolved
(3) NH4Cl + HCl in 0.001 M ammonium chloride solution. What
(4) CH3COOH + CH3COONa will be the OH– ion concentration of this solution:
IE0153 Kb(NH4OH) = 1.8 × 10
–5

–3 –4
125. 50 mL of 2N acetic acid mixed with 10 mL of 1N (1) 3.0 × 10 (2) 9.0 × 10
–3 –4
sodium acetate solution will have an approximate (3) 9.0 × 10 (4) 3.0 × 10
–5
pH of (Ka = 10 ) :– IE0160
(1) 4 (2) 5 (3) 6 (4) 7
132. When 0.02 moles of NaOH are added to a litre
NIE0388
of buffer solution, its pH changes from 5.75 to
126. On addition of NaOH to CH3COOH solution, 60% 5.80. What is its buffer capacity :-
(1) 0.4 (2) 0.05 (3) – 0.05 (4) 2.5
of the acid is neutralised. If pK a of CH3COOH is
IE0161
4.7 then the pH of the resulting solution is :-
(1) More than 4.7 but less than 5.0 ACID, BASE
(2) Less than 4.7 but more than 4.0 –2
133. The conjugated acid of O ions is :-
(3) More than 5.0
+ + + –
(4) Remains unchanged (1) O2 (2) H (3) H3O (4) OH
IE0155 IE0170

127. 500 mL of 0.2 M acetic acid is added to 134. Which ion does not show acidic behaviour :-
500 mL of 0.30 M sodium acetate solution. If the +3 +3
(1)  Al ( H2 O )6  (2) Fe ( H2O )6 
dissociation constant of acetic acid is 1.5 × 10
–5
   
–2 –
then pH of the resulting solution is :- (3) HPO4 (4) ClO3
(1) 5.0 (2) 9.0 (3) 3.0 (4) 4.0 IE0173
IE0156
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
135. In the reaction NH3 + H2O  NH4 + OH
– 143. For two acids A and B, pKa1 = 1.2, pKa2 = 2.8
water behaves as :- respectively in value, then which is true:-
(1) Acid (1) A & B both are equally acidic
(2) Base (2) A is stronger than B
(3) Neutral (3) B is stronger than A
(4) Both acid & Base (4) None of these
IE0175 NIE0391
+ 144. Which of the following is not a Bronsted acid :-
136. The conjugated base of (CH3)2 NH2 is :- + –
(1) CH3NH3 (2) CH3COO
+
(1) CH3NH2 (2) (CH3)2N (3) H2O (4) HSO4
–

(3) (CH3)2N (4) (CH3)2NH IE0185

IE0178 145. In the reaction
+ –
137. Weakest Lowry base is :- 
HNO3 + H2O  H3O + NO3 , the conjugate

®
– –
(1) H (2) OH base of HNO3 is :-
– –
(3) Cl (4) HCO3 (1) H2O (2) H3O
+

NIE0389 – + –
(3) NO3 (4) H3O and NO3
138. Conjugate base of hydrazoic acid is :- IE0187
(1) HN 3− (2) N 3− (3) N (4) N2− 146. The two Bronsted bases in the reaction
– 3– 2– 2–
IE0180 HC2O4 + PO4 
 HPO4 + C2O4 are
– 2–
(1) HC2O4 and PO4
139. NH3 gas dissolves in water to give NH4OH, in
2– 2–
this reaction, water acts as :- (2) HPO4 and C2O4
3– –2
(1) An acid (2) A base (3) PO4 and C2O4
(3) A salt (4) A conjugate base –
(4) HC2O4 and HPO4
2–

IE0181
IE0191
140. Conjugate acid of Zn(OH)2 is :- 147. Which of the following is Bronsted Lowry acid:-
–2 + 2– –
(1) Zn(OH)
+
(2) Zn(OH3)
– (1) SO4 (2) H3O (3) O (4) Cl
2+ IE0194
(3) Zn (4) None
148. The conjugated base for bicarbonate ion is:-
NIE0390
2– –
(1) CO3 (2) HCO3
141. The strongest acid among the following is -
(3) CO2 (4) H2CO3
(1) ClO3(OH) (2) ClO2(OH) IE0195
–
(3) SO(OH)2 (4) SO2(OH)2 149. Conjugated base of OH is :-
IE0184 + + 2–
(1) H2O (2) H3O (3) H (4) O
142. The mixed salt among the following is :- NIE0392
(1) CH(OH)COONa 150. HCl does not behave as acid in :-
|
CH(OH)COONa (1) NH3 (2) C2H5OH (3) H2O (4) C6H6

(2) NaKSO4 IE0197

151. Which of the following is a base according to
(3) CaCl2
(4) All Bronsted Lowry concept :-
– + +
IE0039 (1) I (2) H3O (3) HCl (4) NH4
IE0198
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® Chemistry : Ionic Equilibrium
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152. According to Bronsted concept, the acids in the
154. Which of the following is strongest conjugate base
 + –
following reaction NH3 + H2O  NH4 + OH (1) ClO4
–
(2) HCO3
–

are :- (3) Cl
–
(4) HSO4
–

+
(1) NH3 and NH4 IE0203
(2) H O and OH–
2 155. Which of the following can act both as Bronsted
+
(3) H2O and NH4 acid and Bronsted base :-
2– –2
(1) Na2CO3 (2) O (3) CO3 (4) NH3
(4) NH and OH–
3
IE0207
IE0200

 NH3 + HS ,
–2 –
– 156. For the reaction NH4+ + S 

153. CH3COO ion is a :-
–2
(1) Weak conjugate base NH3 and S are a group of :-
(2) Strong conjugate base (1) Acids (2) Bases
(3) Weak conjugate acid (3) Acid-base pair (4) None of these
(4) Strong conjugate acid IE0216

®
IE0202

EXERCISE-I (Conceptual Questions) ANSWER KEY

Que. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Ans. 2 2 2 2 4 4 2 1 3 1 1 4 1 1 2
Que. 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Ans. 4 1 2 3 4 4 4 1 1 1 1 3 4 4 1
Que. 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
Ans. 2 3 3 4 1 2 4 4 3 1 1 4 2 3 3
Que. 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Ans. 3 3 3 2 3 3 4 4 2 4 3 2 4 3 1
Que. 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75
Ans. 3 3 3 4 3 4 1 4 2 2 3 4 4 2 2
Que. 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90
Ans. 4 2 4 3 1 2 4 3 4 3 3 2 3 2 4
Que. 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105
Ans. 3 1 4 4 2 1 2 4 2 2 1 2 2 2 1
Que. 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
Ans. 2 2 2 3 3 1 4 4 2 1 4 3 3 1 3
Que. 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135
Ans. 1 2 2 3 1 1 1 1 1 2 2 1 4 4 1
Que. 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150
Ans. 4 3 2 1 1 1 2 2 2 3 3 2 1 4 4
Que. 151 152 153 154 155 156
Ans. 1 3 2 2 4 2

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EXERCISE-II (Previous Year Questions) AIPMT/NEET
AIPMT-2014 6. The solubility of AgCl(s) with solubility product
1. Which of the following salts will give highest pH 1.6 × 10
–10
in 0.1 M NaCl solution would be
in water ? –11
(1) 1.6 × 10 M (2) zero
(1) KCl (2) NaCl (3) Na2CO3 (4) CuSO4
–5 –9
IE0241 (3) 1.26 × 10 M (4) 1.6 × 10 M

Re-AIPMT-2015 IE0249

2. Which one of the following pairs of solution is NEET(UG) 2017

not an acidic buffer ? +
7. Concentration of the Ag ions in a saturated
(1) H2CO3 and Na2CO3
–4 –1
(2) H3PO4 and Na3PO4 solution of Ag2C2O4 is 2.2 × 10 mol L

(3) HClO4 and NaClO4 Solubility product of Ag2C2O4 is :-

®
–12 –11
(4) CH3COOH and CH3COONa (1) 2.66 × 10 (2) 4.5 × 10
IE0243 –12 –8
(3) 5.3 × 10 (4) 2.42 × 10
3. What is the pH of the resulting solution when
IE0255
equal volumes of 0.1 M NaOH and 0.01 M HCl
are mixed? NEET(UG) 2018
(1) 7.0 (2) 1.04 (3) 12.65 (4) 2.0
8. Following solutions were prepared by mixing
IE0244
different volumes of NaOH and HCl of different
NEET-I 2016
concentrations :
4. MY and NY3, two nearly insoluble salts, have the
M M
same Ksp values of 6.2 × 10
–13
at room a. 60mL HCl + 40mL NaOH
10 10
temperature. Which statement would be true in
M M
regard to MY and NY3 ? b. 55mL HCl + 45mL NaOH
10 10
(1) The molar solubilities of MY and NY3 in
water are identical. M M
c. 75mL HCl + 25mL NaOH
(2) The molar solubility of MY in water is less 5 5
than that of NY3 M M
d. 100mL HCl + 100mL NaOH
(3) The salts MY and NY3 are more soluble in 10 10
0.5 M KY than in pure water. pH of which one of them will be equal to 1 ?
(4) The addition of the salt of KY to solution of
(1) b (2) a (3) d (4) c
MY and NY3 will have no effect on their
IE0258
solubilities.
–3 –1
IE0247 9. The solubility of BaSO4 in water 2.42 × 10 gL
NEET-II 2016 at 298 K. The value of solubility product (Ksp)
will be
5. The percentage of pyridine (C5H5N) that forms –1
(Given molar mass of BaSO4 = 233 g mol )
+
pyridinium ion (C5H5N H) in a 0.10 M aqueous –10 2 –2
(1) 1.08 × 10 mol L
–9
pyridine solution (Kb for C5H5N = 1.7 × 10 ) is –12 2 –2
(2) 1.08 × 10 mol L
(1) 0.77% (2) 1.6% (3) 1.08 × 10
–14 2
mol L
–2

(3) 0.0060% (4) 0.013% –8

(4) 1.08 × 10 mol L
2 –2

IE0248 IE0259
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® Chemistry : Ionic Equilibrium
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NEET(UG) 2019 NEET (UG) 2020 (COVID-19)

10. pH of a saturated solution of Ca(OH)2 is 9. The 16. Which among the following salt solutions is basic
solubility product (Ksp) of Ca(OH)2 is :- in nature ?
–15 –10
(1) 0.5 × 10 (2) 0.25 × 10 (1) Ammonium chloride
–15 –10
(3) 0.125 × 10 (4) 0.5 × 10 (2) Ammonium sulphate
IE0357 (3) Ammonium nitrate
11. Which will make basic buffer ?
(4) Sodium acetate
(1) 50 mL of 0.1 M NaOH + 25 mL of 0.1 M
IE0415
CH3COOH
17. The solubility product for a salt of the type AB is
(2) 100 mL of 0.1 M CH3COOH + 100 mL of –8
4 × 10 . What is the molarity of its standard
0.1M NaOH solution?
(3) 100 mL of 0.1 M HCl + 200 mL of 0.1 M –4
(1) 2 × 10 mol/L
NH4OH (2) 16 × 10
–16
mol/L

®
(4) 100 mL of 0.1 M HCl + 100 mL of 0.1 M (3) 2 × 10
–16
mol/L
NaOH –4
(4) 4 × 10 mol/L
IE0358
IE0416
NEET(UG) (Odisha) 2019
NEET (UG) 2021
12. The pH of 0.01 M NaOH (aq) solution will be
18. The pKb of dimethylamine and pKa of acetic acid
(1) 7.01 (2) 2
are 3.27 and 4.77 respectively at T (K). The
(3) 12 (4) 9
correct option for the pH of dimethylammonium
IE0359
acetate solution is:
13. Which of the following cannot act both as
(1) 8.50 (2) 5.50 (3) 7.75 (4) 6.25
Bronsted acid and as Bronsted base ?
IE0417
–
(1) HCO3 (2) NH3
NEET(UG) 2021 (Paper-2)
–]
(3) HCl (4) HSO4
19. Silver iodide is used in cloud seeding to produce
IE0360

 + — –7
–11 rain AgI(s)  Ag (aq) + I (aq) ; Ksp =8.5 × 10
14. The molar solubility of CaF2 (Ksp = 5.3 × 10 ) in
0.1 M solution of NaF will be AgNO3 and KI are mixed to give [Ag+] = 0.010M;
–11 –1 –8 –1 [I—] = 0.015 M. Will AgI precipitate?
(1) 5.3 × 10 mol L (2) 5.3 × 10 mol L
(1) Yes
–9 –1 –10 –1
(3) 5.3 × 10 mol L (4) 5.3 × 10 mol L (2) No
IE0361 (3) Can't say
NEET (UG) 2020 (4) Depends on [NO3¯] and [K+]

15. Find out the solubility of Ni(OH)2 in 0.1M NaOH. IE0418

Given that the solubility product of Ni(OH)2 is 20. 100 ml of a mixture of NaOH and Na2SO4 is
–15
2 × 10 .
8 neutralised by 10 ml of 0.5 M H2SO4. Hence
(1) 1 × 10 M
–13 NaOH in 100 ml solution is
(2) 2 × 10 M
(3) 2 × 10 M
–8
(1) 0.2g (2) 0.4 g
–13
(4) 1 × 10 M (3) 0.6 g (4) 0.8 g
IE0414 IE0419

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NEET (UG) 2022 NEET (UG) 2023 (Manipur)
21. The pH of the solution containing 50 mL each 24. For a weak acid HA, the percentage of

of 0.10 M sodium acetate and 0.01 M acetic dissociation is nearly 1% at equilibrium. If the

acid is [Given pKa of CH3COOH = 4.57] concentration of acid is 0.1 mol L–1, then the
correct option for its Ka at the same
(1) 3.57 (2) 4.57
temperature is :
(3) 2.57 (4) 5.57
(1) 1 × 10–4
IE0420 –6
(2) 1 × 10
NEET (UG) 2022 (OVERSEAS)
(3) 1 × 10–5
22. The solubility product of BaSO4 in water is –3
(4) 1 × 10
–9
1.5 × 10 . The molar solubility of BaSO4 in IE0424
0.1 M solution of Ba(NO3)2 is 25. An acidic buffer is prepared by mixing :

®
–8 –8
(1) 0.5 × 10 M (2) 1.5 × 10 M (1) weak acid and it's salt with strong base
–8 –8
(3) 1.0 × 10 M (4) 2.0 × 10 M (2) equal volumes of equimolar solutions of weak
IE0421 acid and weak base
Re-NEET (UG) 2022 (3) strong acid and it's salt with strong base
23. 0.01 M acetic acid solution is 1% ionised, then (4) strong acid and it's salt with weak base
pH of this acetic acid solution is :
(The pKa of acid = pKb of the base)
(1) 3 (2) 2 (3) 4 (4)1
IE0425
IE0422

EXERCISE-II (Previous Year Questions) ANSWER KEY

Que. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Ans. 3 3 3 2 4 4 3 4 1 1 3 3 3 3 2
Que. 16 17 18 19 20 21 22 23 24 25
Ans. 4 1 3 1 2 4 2 3 3 1

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® Chemistry : Ionic Equilibrium
Pre-Medical

EXERCISE-III (Analytical Questions) Master Your Understanding

1. pH of the solution of HCOONH4 is 6.48 this can 9. How much of 0.2 N NaOH is required to
be explained by :- completely neutralize 100 mL of 0.5 N H2SO4
(1) 200 mL (2) 250 mL
(1) Hydrolysis of both cation and anion
(3) 300 mL (4) 350 mL
(2) Hydrolysis of cation
NIE0396
(3) Hydrolysis of anion
–2
(4) Hydrolysis of water 10. Conjugate base of HPO4 is :–
–3 –2
IE0273 (1) PO4 (2) HPO4
2. The correct representation of solubility product (3) H3PO4 (4) H2PO4
–

of SnS2 is :- NIE0397
4+ 2– 2 4+ 2–
(1) [Sn ][S ] (2) [Sn ][S ] 11. Solution with pH = 0 is :–
4+
(3) [Sn ][2S ]
2– 4+
(4) [Sn ][2S ]
2– 2
(1) Acidic (2) Neutral
IE0274 (3) Basic (4) Amphoteric

®
NIE0398
3. A solution of FeCl3 in water acts as acidic due to:-
–
(1) Acidic impurities (2) Ionisation 12. Conjugate acid of HS is :–
–2
3+ (1) H2S (2) S
(3) Hydrolysis of Fe (4) Dissociation
(3) Both the above (4) None
IE0275 NIE0399
4. The pKa of HNO2 is 3.37. The pH of HNO2 in 13. How many grams of dibasic acid (mol. wt. = 200)
–1
its 0.01 mol L aqueous solution will be :- should be present in 100 mL of the aqueous
solution to give strength of (N/10) :–
(1) 5.37 (2) 2.69 (3) 1.69 (4) 0.69
(1) 1g. (2) 2g. (3) 5g. (4) 10g.
IE0276
NIE0400
–10
5. If ksp of CaF2 in pure water is 1.70 × 10 , then 14. An alcoholic drinks substance pH = 4.7 then
–
find the solubility of CaF2 in 0.10M NaF solution:- OH ion concentration of this solution is:-
–14 2 –2
(1) 1.70 × 10
–10
(2) 1.70 × 10
–9
(Kw = 10 mol L )
–10 –10
(3) 1.70 × 10
–8
(4) 0.10 M (1) 3 × 10 (2) 5 × 10
–10 –8
NIE0394 (3) 1 × 10 (4) 5 × 10
6. The pKa of a weak acid HA is 4.80. The pKb of NIE0401
weak base BOH is 4.78. The pH of an aqueous 15. HCO3− is a conjugate acid of :–
solution of the corresponding salt BA will be : (1) H2CO3 (2) HCOOH
(1) 9.58 (2) 4.79 (3) 7.01 (4) 9.22 2−
(3) CO 3 (4) CO2
IE0294
NIE0402
7. How many litres of water must be added to
–4 +
1 litre of an aqueous solution of HCl with a pH 16. An aqueous solution contains 10 [H ]. If it is
of 1 to create an aqueous solution with pH of 2 ? diluted by mixing equal volume of water then the
– –3
(1) 0.1 L (2) 0.9 L concentration of OH in mol dm will be :–
–10 –10
(3) 2.0 L (4) 9.0 L (1) 0·5 × 10 (2) 2 × 10
NIE0395 (3) 10
–6
(4) 10
–8

8. Concentrations of NH4Cl and NH4OH in a buffer IE0317

solution are in the ratio 1 : 10. If Kb for NH4OH 17. Which of the following is right for diprotic acid :
–10
is 10 , then pH of the buffer is :– (1) Ka2 > Ka1 (2) Ka1 > Ka2
(1) 4 (2) 5 (3) 9 (4) 11 1
(3) Ka2 > (4) Ka2 = Ka1
Ka1
IE0312
IE0318

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18. The first and second dissociation constants of an acid 24. Ionisation constant of CH3COOH is 1.7 × 10 and
–5

–5 –10
H2A are 1.0 × 10 and 5.0 × 10 respectively. + –4
concentration of H ions is 3.4 × 10 . Then find
The overall dissociation constant of the acid will be:-
(1) 5.0 × 10
15
(2) 5.0 × 10
–15 out initial concentration of CH3COOH molecules:
–4 –3
5 –5 (1) 3.4 × 10 (2) 3.4 × 10
(3) 0.2 × 10 (4) 5.0 × 10 –4 –3
(3) 6.8 ×10 (4) 6.8 × 10
IE0319
NIE0405
+
19. The concentration of [H ] and concentration of 25. Solubility of a M2S salt is 3.5 × 10
–6
then find
–
[OH ] of a 0.1 M aqueous solution of 2% ionised
–14 out solubility product :-
weak acid is [ionic product of water = 1 × 10 ]:- –6 –16
–3 –11 (1) 1.7 × 10 (2) 1.7 × 10
(1) 0.02 × 10 M and 5 × 10 M –18 –12
–3 –11
(3) 1.7 × 10 (4) 1.7 × 10
(2) 1 × 10 M and 3 × 10 M
NIE0406
–3 –12
(3) 2 × 10 M and 5 × 10 M 26. The solubility product of a sparingly soluble salt

®
–11 –1
–2
(4) 3 × 10 M and 4 × 10
–13
M AX2 is 3·2 × 10 . Its solubility (in mol L ) is :-
–4 –4
IE0267 (1) 3·1 × 10 (2) 2 × 10
–4 –6
20. When HCl gas is passed through saturated solution (3) 4 × 10 (4) 5·6 × 10
of common salt, pure NaCl get precipitated because: NIE0407
–
(1) In aqueous solution Cl obtained from dissociation
27. What volume of 0.1M H2SO4 is needed to completely
of HCl which reduces the solubility product of
neutralize 40 mL of 0.2M NaOH solution–
NaCl. (1) 10 mL (2) 40 mL (3) 20 mL (4) 80 mL
(2) More water is needed to dissociate HCl gas. IE0302
(3) Impurities of NaCl solution dissolves in HCl. 28. If pH value of a solution is 3 and by adding water,
+ –
(4) Ionic product of [Na ] [Cl ] > solubility product it becomes 6, then the dilution is increased by :
of NaCl. (1) 10 times (2) 100 times
(3) 500 times (4) 1000 times
NIE0403
IE0303
21. The solubility of BaSO4 in water, is
29. The pH value of decinormal solution of NH4OH,
–3 –1
2.33 × 10 gL . Its solubility product will be which is 20% ionised is :–
(molecular weight of BaSO4 = 233) :- (1) 13.30 (2) 14.70 (3) 12.30 (4) 12.95
–5 –10 NIE0408
(1) 1 × 10 (2) 1 × 10
–
–15 –20 30. Conjugate acid of NH2 ion is
(3) 1 × 10 (4) 1 × 10 + –2
(1) NH4OH (2) NH4 (3) NH (4) NH3
IE0268
NIE0409
+
22. What will be the H ion concentration, when 4 g +
31. Which statement is wrong about pH and H :
NaOH is dissolved in 1000 mL of water:
(1) 10
–1
(2) 10
–13
(3) 10
–4
(4) 10
–10 (1) pH of neutral water is not zero
(2) Adding 1N, solution of CH3COOH and
IE0269
NaOH each pH will be seven
23. Which of the following will not undergo hydrolysis
in water :- (3) pH of dilute H2SO4 > pH of concentrate
(1) Sodium sulphate H2SO4
(2) Ammonium sulphate (4) Mixed solution of CH3COOH and HCl, have
(3) Calcium sulphate pH less than 7
(4) All the salts will hydrolyse NIE0410
NIE0404

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Pre-Medical
32. 1 M and 2.5 litre NaOH solution mixed with 40. The ionization constant of ammonium hydroxide
–5
another 0.5 M and 3 litre NaOH solution. Then is 1.77 × 10 at 298 K. Hydrolysis constant of
find out molarity of resultant solution :- ammonium chloride is :-
–12 –10
(1) 0.80 M (2) 1.0 M (3) 0.73 M (4)0.50 M (1) 5.65 × 10 (2) 5.65 × 10
NIE0411 (3) 6.50 × 10
–12
(4) 5.65 × 10
–13

33. Solution of 0.1 N NH4OH and 0.1 N NH4Cl has IE0225

–
pH 9.25, Then find out pKb of NH4OH:- 41. What is the [OH ] in the final solution prepared
(1) 9.25 (2) 4.75 (3) 3.75 (4) 8.25 by mixing 20.0 mL of 0.050 M HCl with 30.0 mL
NIE0412 of 0.10M Ba(OH)2 ?
34. Which of the following pairs constitutes a buffer:- (1) 0.12 M (2) 0.10 M
(3) 0.40 M (4) 0.0050M
(1) HNO2 & NaNO2
IE0226
(2) NaOH & NaCl
42. In a buffer solution containing equal concentration
(3) HNO3 & NH4NO3 – – –10
of B and HB the Kb for B is 10 . The pH of
(4) HCl & KCl
buffer solution is :-

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IE0218
(1) 4 (2) 10 (3) 7 (4) 6
–8 IE0229
35. The hydrogen ion concentration of a 10 M HCl
–14
aqueous solution at 298 K (KW = 10 ) is :- 43. The pH of blood from 7.26 to 7.42 is maintained
–6
(1) 1.0 × 10 M by buffer :-
–7 –
(2) 1.0525 × 10 M (1) H2CO3/HCO3
–8
(3) 9.525 × 10 M (2) H3PO4/H2PO4
–

–8
(4) 1.0 × 10 M (3) CH3COOH/CH3COO
–

IE0219 –
(4) NH2–CH2COOH/NH2CH2COO
–5
36. A weak acid HA has a Ka of 1.00 × 10 . If
NIE0393
0.100 moles of this acid is dissolved in one litre
of water the percentage of acid dissociated at 44. A buffer solution is prepared in which the
equilibrium is closed to :- concentration of NH3 is 0.30 M and the
(1) 99.0% (2) 1.00% +
concentration of NH4 is 0.20 M. If the
(3) 99.9% (4) 0.100% –5
equilibrium constant, Kb for NH3 equals 1.8 × 10 ,
IE0222
what is the pH of this solution ? (log 2.7 = 0.43)
37. Calculate the pOH of a solution at 25° C that (1) 9.08 (2) 9.43 (3) 11.72 (4) 8.73
–10 +
contains 1×10 M of hydronium ions, i.e., H3O IE0233
(1) 7.000 (2) 4.000 (3) 9.000 (4) 1.000
IE0221 45. If pH of a saturated solution of Ba(OH)2 is 12,
the value of its K(sp) is :-
38. Equimolar solutions of the following were –7 3 –6 3
(1) 5.00 × 10 M (2) 4.00 × 10 M
prepared in water separately. Which one of the –7 3 –6 3
solutions will record the highest pH? (3) 4.00 × 10 M (4) 5.00 × 10 M
(1) BaCl2 (2) MgCl2 (3) CaCl2 (4) SrCl2 IE0228
IE0223 46. Buffer solutions have constant acidity and
alkalinity because:
39. Equal volumes of three acid solutions of pH 3, 4 + –
(1) they have large excess of H or OH ions
and 5 are mixed in a vessel. What will be the
+ (2) they have fixed value of pH
H ion concentration in the mixture ?
–4 –3
(3) these give unionised acid or base on reaction
(1) 3.7 × 10 M (2) 3.7 × 10 M with added acid or alkali
–3 –4
(3) 1.11 × 10 M (4) 1.11 × 10 M (4) acids and alkalies in these solutions are
shielded from attack by other ions
IE0224
IE0236

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Pre-Medical
47. Equimolar solutions of the following substances 48. Which is the strongest acid in the following ?
were prepared separately. Which one of the these (1) H2SO3 (2) H2SO4
will record the highest pH value? (3) HClO3 (4) HClO4
(1) LiCl (2) BeCl2 (3) BaCl2 (4) AlCl3 IE0239
IE0237

EXERCISE-III (Analytical Questions) ANSWER KEY

Que. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Ans. 1 1 3 2 3 3 4 2 2 1 1 1 1 2 3
Que. 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Ans. 2 2 2 3 4 2 2 1 4 2 2 2 4 3 4
Que. 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
Ans. 2 3 2 1 2 2 2 1 1 2 2 1 1 2 1
Que. 46 47 48
Ans. 3 3 4

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Pre-Medical

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