Multiple Choice
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1.
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A buffer is prepared by adding 0.4 mol of solid NaOH to 1.0 L of 1.0 M acetic
acid. Which of the following statements is true?
A) | The pH of the solution will be equal to the pKa of the acid. | B) | The pH of the
solution will be greater than the pKa of the acid. | C) | The pH of the solution will be less than the
pKa of the acid. | D) | More information is needed to solve this problem. |
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2.
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What is the pH of a 0.0100 M sodium benzoate solution? Kb
(C7H5O2–) = 1.5x10–10
A) | 5.91 | B) | 8.09 | C) | 0.38 | D) | 13.62 |
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3.
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When a weak acid is titrated with a strong base, the pH at the equivalence point
is
A) | greater than 7.0 | B) | equal to 7.0 | C) | less than
7.0 | D) | equal to the pKa of the acid |
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4.
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Which of the following will form a buffer when dissolved in water to make 1 L of
solution?
A) | 0.2 mol of NaCl and 0.2 mol HNO3 | B) | 0.2 mol NaOH and 0.2
mol HCl | C) | 0.4 mol HC2H3O2 and 0.4 mol NaOH | D) | 0.4 mol
NH3 and 0.2 mol HCl |
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5.
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A 20.0-mL sample of 0.25M HCl is titrated with 0.15M NaOH. What is the pH
of the solution after 30.0 mL of the base have been added?
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6.
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The solubility of Cu(IO3)2 in water is
3.27x10–3 M. What is the Ksp?
A) | 3.50x10–8 | B) | 2.14x10–5 | C) | 1.40x10–7 | D) | 4.28x10–5 |
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7.
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What is the [H3O+] in a solution that consists
of 1.5 M NH3 and 2.5 M NH4Cl? (Kb = 1.8
x10–5)
A) | 9.3 x10–10 M | B) | 1.1 x10–5
M | C) | 3.3 x10–10 M | D) | 3.0 x10–5
M |
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8.
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Which of the following has the highest buffer capacity?
A) | 0.10 M H2PO4– / 0.50 M
HPO42– | B) | 0.50 M
H2PO4– / 0.10 M
HPO42– | C) | 0.10 M
H2PO4– / 0.10 M
HPO42– | D) | 0.50 M
H2PO4– / 0.50 M
HPO42– |
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9.
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What is the pKa for the acid HA if a solution of 0.65M HA and 0.85M NaA has a pH
of 4.75?
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10.
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Which of the following mixtures would be a buffer system?
A) | CH3COOH , NaH2PO4 | B) | HSO4– ,
HSO3– | C) | H2CO3 ,
HCO3– | D) | H2PO4– ,
HCO3– |
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11.
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What will be the effect of adding 0.5 mL of 0.1 M HCl to 100 mL of a phosphate
buffer in which [H2PO4–] =
[HPO42–] = 0.35 M?
A) | The pH will increase significantly | B) | The pH will decrease
significantly | C) | The pH will increase slightly | D) | The pH will decrease
slightly |
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12.
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Which of the following statements is true for the titration of a weak acid with
a strong base?
A) | At the equivalence point, the [H+] equals the ionization
constant of the acid | B) | The pH is 7 at the equivalence
point | C) | The graph of pH versus the volume of base added rises gradually at first and then
much more rapidly | D) | The graph of pH versus the volume of base added
shows no sharp rise |
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