Chapter 17 Multiple-choice questions

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. Which of the following structures represents the conjugate acid of HPO₄^2-

H₂PO₄^- correct incorrect

H₃PO₄ correct incorrect

H₄PO₄⁺ correct incorrect

PO₄^3- correct incorrect

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. Which one of the following is equal to the pK_a of a weak acid?

Its relative molecular mass correct incorrect

The pK_b of its conjugate base correct incorrect

The pH of a solution containing equal amounts of the acid and its conjugate base correct incorrect

The equilibrium concentration of its conjugate base correct incorrect

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. Which of the following relationships is true for an acidic solution at 25ºC?

[H₃O⁺] > [OH^-] correct incorrect

pH > 7.00 correct incorrect

K_w > 1 × 10^-14 correct incorrect

The solution is negatively-charged correct incorrect

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. Which one of the following relationships is true in water at 25ºC?

[H₃O⁺] = [H₂O] correct incorrect

[OH^-] = [H₂O^-] correct incorrect

K_w > 1 × 10^-14 correct incorrect

[H₃O⁺] = [OH^-] correct incorrect

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. A solution of HCl with a concentration of 4 × 10^-4 mol L^-1 has a pH of which of the following?

2.67 correct incorrect

3.21 correct incorrect

3.40 correct incorrect

4.31 correct incorrect

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. An aqueous solution containing a concentration of 2.5 × 10^-8 OH^- ions will have a pH of which of the following?

6.40 correct incorrect

6.42 correct incorrect

7.40 correct incorrect

7.60 correct incorrect

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. Which of the following is not an example of a weak acid?

Lactic acid correct incorrect

Carbonic acid correct incorrect

Sulfuric acid correct incorrect

Pyruvic acid correct incorrect

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. A buffer solution comprises which of the following?

A weak acid in solution correct incorrect

A strong acid in solution correct incorrect

A weak base in solution correct incorrect

A weak acid and its conjugate base in solution correct incorrect

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. A buffer solution contains ethanoic acid and its conjugate base; the pK_a of ethanoic acid is 4.74. At what pH does the solution buffer?

3.0 correct incorrect

4.0 correct incorrect

5.0 correct incorrect

6.0 correct incorrect

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. A strong acid has a large K_a value. True or false?

True correct incorrect

False correct incorrect

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. An amino acid can act as an acid and a base. True or false?

True correct incorrect

False correct incorrect