43. The equilibrium constant for the autonionization of water (shown below) increases with
increasing temperature, from 1.01 x10–14 at 25C to 5.31 x10–14 at 50C.
H2O(l) + H2O(l) H3O+(aq) + OH–(aq)
Which of the following statements is consistent with this behaviour?
A)
The autoionization of water is an endothermic reaction.
B)
The autoionization of water is an exothermic reaction.
C)
The hydronium ion concentration at equilibrium increases with increasing
temperature.
D)
The hydronium ion concentration at equilibrium decreases with increasing
temperature.
E)
Both A and C.
44. What is the equilibrium concentration of amide ion (NH2–) in liquid ammonia at 25°C?
(“am” = dissolved in ammonia)
2NH3(l) NH4+(am) + NH2–(am); Kc = 1.8 10–24 at 25°C
A)
2.6 10–12 M
B)
3.6 10–24 M
C)
1.3 10–12 M
D)
1.8 10–24 M
E)
9.0 10–25 M
45. What is the hydronium-ion concentration in a solution formed by combining 750 mL of
0.10 M NaOH with 250 mL of 0.30 M HCl?
NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)
A)
0.075 M
B)
1.7 10–13 M
C)
1.0 10–7 M
D)
0.30 M
E)
0.10 M
Test Bank General Chemistry, 10th edition 14
46. At 20°C, the ion-product constant of water, Kw, is
6.88 10−15
. What is the pH of pure water
at 20°C?
A)
7.000
B)
6.501
C)
7.181
D)
7.081
E)
none of these
47. The concentration of H3O+ in a solution is 7 10–4 M at 25°C. What is its hydroxide-ion
concentration?
A)
7 10–4 M
B)
1 10–10 M
C)
2 10–10 M
D)
3 10–10 M
E)
1 10–11 M
48. At 25C a solution has a hydroxide-ion concentration of 4.94 10–5 M. What is its
hydronium-ion concentration?
A)
4.94 10–19 M
B)
1.00 10–7 M
C)
1.00 10–14 M
D)
4.94 10–5 M
E)
2.02 10–10 M
49. What is the hydronium-ion concentration of a 0.0087 M LiOH solution?
A)
1.1 10–12 M
B)
8.7 10–3 M
C)
1.0 10–14 M
D)
1.0 10–7 M
E)
8.7 10–17 M
Test Bank General Chemistry, 10th edition 15
50. What is the hydronium-ion concentration of a 0.0038 M Ba(OH)2 solution?
A)
7.6 10–3 M
B)
3.8 10–3 M
C)
1.3 10–12 M
D)
2.6 10–12 M
E)
1.0 10–7 M
51. Which of the following expressions is not equivalent to pH?
A)
–log [H+(aq)]
B)
C)
14.0 – pOH
D)
E)
–log Kw
52. A solution in which the pH is 1.5 would be described as
A)
neutral.
B)
very acidic.
C)
slightly basic.
D)
slightly acidic.
E)
very basic.
53. A solution has a hydroxide-ion concentration of 0.0030 M. What is the pOH of the solution?
A)
11.48
B)
2.52
C)
7.00
D)
8.19
E)
5.81
Test Bank General Chemistry, 10th edition 16
54. What is the pH of a 0.051 M HClO4 solution?
A)
15.29
B)
2.98
C)
12.71
D)
1.29
E)
11.02
55. What is the pOH of a 0.044 M HI solution?
A)
3.12
B)
12.64
C)
10.88
D)
15.36
E)
1.36
56. What is the pH of the final solution when 25 mL of 0.025 M HCl has been added to 35 mL
of 0.040 M HCl at 25°C?
A)
3.22
B)
1.78
C)
1.47
D)
2.69
E)
3.39
57. What is the pH of a 0.0042 M hydrochloric acid solution?
A)
5.47
B)
11.62
C)
7.00
D)
8.53
E)
2.38
Test Bank General Chemistry, 10th edition 17
58. The hydronium-ion concentration of a solution is 2.5 10–6 M. What is the pH of the
solution?
A)
6.81
B)
3.77
C)
2.00
D)
5.60
E)
10.60
59. At 25°C, what is the pH of a 10.0 M HBr solution?
A)
1.000
B)
0.000
C)
10.000
D)
–1.000
E)
14.000
60. Which aqueous solution has the lowest pH?
A)
0.30 M HCl
B)
0.30 M NaOH
C)
0.30 M NH3
D)
0.30 M Ba(OH)2
E)
0.30 M H2SO4
61. What pH should a solution have if its pH is about the same as that of vinegar?
A)
about 8
B)
about 11
C)
about 1
D)
about 6
E)
about 3
62. A solution has a pH value of 3.76. What is the pOH for this solution?
A)
7.00
B)
3.72
C)
3.76
D)
1.74
E)
10.24
63. Which solution has the highest pH?
A)
0.1 M Ba(OH)2
B)
0.1 M CH3COOH
C)
0.1 M HCl
D)
0.1 M NH3
E)
0.1 M NaOH
64. The pOH of a solution is 5.22. What is the pH of the solution?
A)
5.22
B)
8.78
C)
6.03
D)
7.00
E)
2.68
65. What is the pH of a 0.0035 M Ba(OH)2 solution?
A)
9.04
B)
11.54
C)
2.46
D)
11.85
E)
2.15
66. What is the pOH of a 0.0055 M Ba(OH)2 solution?
A)
9.49
B)
11.74
C)
12.04
D)
1.96
E)
2.26
67. A solution has a hydronium-ion concentration of 0.0082 M. What is its pOH?
A)
2.09
B)
16.09
C)
9.20
D)
4.80
E)
11.91
68. A solution has a hydroxide-ion concentration of 0.043 M. What is its pH?
A)
15.37
B)
12.63
C)
17.15
D)
7.00
E)
1.37
69. What is the pOH of a 0.065 M HNO3 solution?
A)
12.81
B)
11.27
C)
15.19
D)
1.19
E)
2.73
70. What is the pH of a 0.0086 M LiOH solution?
A)
9.24
B)
11.93
C)
2.07
D)
4.76
E)
16.07
71. What is the pOH of a 0.0092 M CsOH solution?
A)
2.04
B)
16.04
C)
9.31
D)
4.69
E)
11.96
72. What is the pH of a solution prepared by dissolving 0.739 g of NaOH(s) in 4.50 L of water?
A)
1.733
B)
12.267
C)
7.000
D)
11.613
E)
2.387
73. What is the pOH of a solution prepared by dissolving 0.287 g of KOH(s) in 7.00 L of water?
A)
10.864
B)
3.136
C)
2.291
D)
11.709
E)
7.000
Test Bank General Chemistry, 10th edition 21
74. What is the pH of a solution prepared by dissolving 0.365 L of HCl(g), measured at STP, in
enough water such that the total volume of the solution is 6.00 L?
(R = 0.0821 L · atm/(K · mol))
A)
2.566
B)
11.434
C)
1.788
D)
7.000
E)
12.212
75. What is the pOH of a solution prepared by dissolving 0.465 L of HCl(g), measured at STP,
in enough water such that the total volume of the solution is 4.50 L?
(R = 0.0821 L · atm/(K · mol))
A)
12.317
B)
7.000
C)
1.683
D)
11.664
E)
2.336
76. Which of the following solutions has the highest hydroxide-ion concentration?
A)
0.1 M HCl
B)
a solution with pH = 5
C)
0.1 M H2SO4
D)
pure water
E)
a solution with pOH = 12
77. A solution has a pH of 10.20 at 25°C. What is the hydroxide-ion concentration at 25°C?
A)
3.8 M
B)
2.2 10–2 M
C)
1.6 10–4 M
D)
6.3 10–11 M
E)
1.0 10–7 M
78. A solution has a pOH of 5.36. What is its hydroxide-ion concentration?
A)
1.8 10–4 M
B)
5.4 M
C)
2.3 10–9 M
D)
4.4 10–6 M
E)
4.7 10–3 M
79. The pOH of a solution is 5.06. What is its hydronium-ion concentration?
A)
1.1 105 M
B)
1.1 10–9 M
C)
8.7 10–6 M
D)
5.06 M
E)
6.3 10–3 M
80. The pH of a solution of a strong base is 10.27 at 25°C. What is its hydronium-ion
concentration?
A)
2.9 10–3 M
B)
1.9 10–4 M
C)
1.4 10–4 M
D)
5.4 10–11 M
E)
1.4 10–2 M
81. What is the hydroxide-ion concentration in a solution formed by combining 200. mL of
0.15 M HCl with 300. mL of 0.090 M NaOH at 25°C?
HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)
A)
1.7 10–13 M
B)
0.090 M
C)
1.7 10–12 M
D)
0.054 M
E)
1.0 10–7 M
82. Which solution would cause blue litmus to turn red?
A)
a solution of pH 10
B)
a solution of 0.01 M NH3
C)
a solution of pOH 4
D)
a solution of 0.005 M CH3COOH
E)
a solution of 0.10 M NaOH