Chapter 17 - Acid-Base (Proton Transfer) Reactions

Chapter 17 - Acid-Base (Proton Transfer) Reactions

According to the Arrhenius definition, what is the substance that provides hydroxide ions in solution?

Solvent

Precipitate

Base

Acid

Salt

According to Arrhenius theory, what is an acid?

A. A substance that contains a high concentration of hydrogen ions in solutions with water.

B. A substance that will lower the hydrogen ion concentration when placed in water.

C. A substance that has an H in its formula.

D. An electron pair donor.

E. An electron pair acceptor.

Which of the following is not capable of acting like a Brønsted–Lowry base?

A. H₂O()

B. NH₄⁺ ion

C. Cl^– ion

D. HNO₃(aq)

E. H₂PO₄^–(aq)

Which of the following cannot act as a Brønsted–Lowry acid?

A. HCO₃^–(aq)

B. HOH()

C. NH₃(g)

D. CO₃^2–(aq)

E. CH₃OH()

Consider the following generalized reaction.

For this reaction, which of the following is correct?

A. A is proton source.

B. B is a proton remover.

C. A is an electron pair donor.

D. B is an electron pair acceptor.

E. This a Lewis acid-base reaction.

Which of the following is a Lewis acid but not a Brønsted–Lowry acid?

A. OH^–

B. HPO₄^2–

C. HCl

D. NH₄⁺

E. Fe³⁺

Which one of the following pairs does not represent a conjugate acid-base pair?

H₃PO₄ / HPO₄^2-

H₂O / OH^-

HBr / Br^-

NO₃^- / HNO₃

HClO₂ / ClO₂^-

Choose the pair that does not constitute a conjugate acid-base pair.

CH₃CO₂H / CH₃CO₂^-

H₃O⁺ / H₂O

HSO₄^- / SO₄^2-

H₃PO₄ / HPO₄^2-

None. All of these are conjugate acid base pairs.

Which one of the following is a strong acid?

nitric acid, HNO₃

phosphoric acid, H₃PO₄

hypobromous acid, HOBr

bromic acid, HBrO₃

carbonic acid, H₂CO₃

Given the following relative acid strengths, starting with the weakest: HCO₃^– < HNO₃ < HBr, what is the relative strength of each conjugate base, starting with the weakest?

A. CO₃^2– < NO₃^– < Br^–

B. Br^– < CO₃^2– < NO₃^–

C. NO₃^– < Br^– < CO₃^2–

D. Br^– < NO₃^–< CO₃^2–

E. CO₃^2– < Br^– < NO₃^–

Which of the following is the correct net ionic equation for the reaction between nitrous acid and hydrogen sulfide ion?

A. HNO₂ + HS^– H₂NO₂⁺ + S^2–

B. HNO₂ + HS^– NO₂^– + H₂S

C. HNO₂ + HSO₄^– H₂NO₂⁺ + SO₄^2–

D. HNO₂ + HSO₄^– NO₂^– + H₂SO₄

E. HNO₃ + HSO₄^– NO₃^– + H₂SO₄

Which is the correct net ionic equation for the reaction between HC₂O₄^– and HPO₄^2–? (Note: H₂C₂O₄ is a stronger acid than H₂PO₄^–.)

A. HC₂O₄^– + HPO₄^2– H⁺ + H₂O₄^2– + HPO₄^2–

B. HC₂O₄^– + HPO₄^2– H⁺ + HC₂O₄^– + PO₄^3–

C. HC₂O₄^– + HPO₄^2– C₂O₄^2– + H₂PO₄^–

D. HC₂O₄^– + HPO₄^2– H₂C₂O₄ + PO₄^3–

E. HC₂O₄^– + HPO₄^2– H₂ + C₂O₄^2– + PO₄^3–

Which one of the following chemical equations illustrates the ionization of perchloric acid, HClO₄, when it dissolves in water?

2 HClO₄2 ClO₄^- + H₂

HClO₄ + H₂O H₃O⁺ + ClO₄^-

HClO₄ + OH^- H₂O + ClO₄^-

3 HClO₄ + 2 H₂O 2 H₂O⁺ + 3 HClO₄^-

HClO₄ + H₂O H₂ClO₄⁺ + OH^-

Which of the following statements is incorrect?

A. Acid-base reactions involve a transfer of protons; redox reactions involve a transfer of electrons.

B. In both redox and acid-base reactions, the reactants are given special names to indicate their roles in the transfer process.

C. Just as certain species can either donate or accept protons and thereby behave as an acid in one reaction and a base in another, certain species can either accept or donate electrons, acting as an oxidizing agent in one reaction and a reducing agent in another.

D. Just as acids and bases may be classified as "strong" or "weak" depending on how readily they donate or accept protons, the strengths of oxidizing and reducing agents may be compared according to their tendencies to attract or release electrons.

E. Unlike most acid-base reactions in solution, which reach a state of equilibrium, most aqueous redox reactions do not reach a state of equilibrium and proceed entirely either in the forward or reverse direction.

The autoionization of water, as represented by the below equation, is known to be endothermic. Which of the following correctly states what occurs as the temperature of water is raised? H₂O(l) + H₂O(l) H₃O⁺(aq) + OH^–(aq)

The pH of the water does not change, and the water remains neutral.

The pH of the water decreases, and the water remains neutral.

The pH of the water increases, and the water becomes more acidic.

The pH of the water decreases, and the water becomes more acidic.

The pH of the water increases and the water remains neutral.

Which of the following statements is incorrect?
i. K_w = [H⁺][OH^–] = 1.0 × 10^–14 at 25°C.
ii. Water or water solutions in which [H⁺] = [OH^–] = 10^–7 M are neutral solutions, neither acidic nor basic.
iii. A solution in which [H⁺] > [OH^–] is basic.
iv. A solution in which [OH^–] > [H⁺] is acidic.

A. i and ii

B. iii and iv

C. ii, iii, and iv

D. All statements are correct.

E. All statements are incorrect.

At 55°C, the ion-product constant of water, K_w, is 7.05 × 10^-14. The pH of pure water at 55°C is

4.384

7.000

3.804

4.484

None of these choices are correct.

Carbonic acid is a diprotic acid, H₂CO₃, with K_a1 = 4.2 × 10^–7 and K_a2 = 4.8 × 10^–11 at 25°C. The ion product for water is K_w = 1.0 × 10^–14 at 25°C. What is the OH^– concentration of a solution that is 0.15 M in Na₂CO₃?

2.7 × 10^-6 M

6.0 × 10^-5 M

5.6 × 10^-3 M

2.1 × 10^–4 M

2.5 × 10^-4 M

What is the [ OH^- ] in a solution that has a pH of 10.15 ?

1.41×10^-4 M

0.213 M

1.41×10^-5 M

7.08×10^-10 M

7.08×10^-11 M

Which of the following is true for a basic solution?

[ H⁺ ] < [ OH^- ]

K_w = [ H⁺ ]

[ OH^- ] = [ H⁺ ]

[ H⁺ ][ OH^- ] = 1

[ OH^- ] < [ H⁺ ]

What is the pH of a solution when [OH^-] = 5.0×10^-2 mol/L?

12.70

7.00

13.70

0.30

1.30

What is the [ H⁺ ] of a solution that has a pH of 7.37?

4.27×10⁶

2.34×10^-7

4.27×10^-8

2.34×10⁷

Which one of the following is not characteristic of a acid?

Producing a solution with a pH less than 7

Tasting sour

Producing hydrogen ions in solution

Turning red litmus blue

If the pH of a solution is equal to 7.00, the solution is _____.

basic

amphoteric

neutral

acidic

The pH of a solution is 5.330. Find [OH^–].

A. [OH^–] = 2.14 × 10^–9 molar

B. [OH^–] = 4.70 × 10^–11 molar

C. [OH^–] = 5.33 × 10^–7 molar

D. [OH^–] = 4.70 × 10^–6 molar

E. [OH^–] = 5.33 molar

A solution is made by dissolving 12.50 g of NaOH, a strong base, in water to produce 2.0 liters of solution. What is the pH of this solution?

A. 13.50

B. 13.19

C. 11.74

D. 0.81

E. 0.31

The following three equations represent equilibria that lie to the right.

HNO₃(aq) + CN^–(aq) HCN(aq) + NO₃ ^–(aq)

HCN(aq) + OH^–(aq) H₂O(l) + CN^–(aq)

H₂O(l) + CH₃CH₂O^–(aq) CH₃CH₂OH(aq) + OH^–(aq)

Identify the strongest base.

A. CH₃CH₂O^–

B. NO₃^–

C. CN^–

D. CH₃CH₂OH

E. H₂O

Carbonic acid is a diprotic acid, H₂CO₃, with K_a1 = 4.2 × 10^–7 and K_a2 = 4.8 × 10^–11 at 25°C. The ion product for water is K_w = 1.0 × 10^–14 at 25°C. What is the OH^– concentration of a solution that is 1.15 M in Na₂CO₃?

7.4 × 10^-6 M

1.7 × 10^-4 M

2.1 × 10^–4 M

6.9 × 10^-4 M

1.5 × 10^-2 M

As water is heated, its pH decreases. This means that

the dissociation of water is an endothermic process.

the water has a lower [OH^–] than cooler water.

the K_w value is decreasing.

the water is no longer neutral.

None of these choices are correct.

Calculate the pH of a 8.22×10^-2 M NaF solution (K_b = 1.4 x 10^-11).

11.94

2.06

5.97

3.15

8.03

At 65°C, the ion-product constant of water, K_w, is 1.20 × 10^-13. The pH of pure water at 65°C is

3.727

7.000

4.307

4.407

None of these choices are correct.

Calculate the hydroxide concentration in a 3.0 M HCl aqueous solution.

3.0*10^-14 M

7.0*10^-13 M

1.0*10^-7 M

3.4*10^-15 M

3.0*10^14 M