Question 1

Which of the following statements best explains why hydrochloric acid (HCl) is used by the stomach to aid digestion?

Accepted Answer

HCl activates enzymes that break down food and kills unwanted bacteria.

Question 2

Which of the following is NOT a property of acids?

Accepted Answer

Bitter taste

Question 3

According to the Arrhenius definition, which equation correctly represents the dissociation of a strong acid in water?

Accepted Answer

$$\mathrm{HCl}(aq) + \mathrm{H}_2\mathrm{O}(l) \rightarrow \mathrm{H}_3\mathrm{O}^+(aq) + \mathrm{Cl}^-(aq)$$

Question 4

Which of the following substances can act as both a Brønsted-Lowry acid and a base?

Accepted Answer

H$$_2O$$

Question 5

A solution has $$[\mathrm{H}_3\mathrm{O}^+] = 1 	imes 10$$^{-4}$$\ \mathrm{M}. $$What is its pH?

Accepted Answer

$$4$$

Question 6

Which of the following is a conjugate acid–base pair?

Accepted Answer

$$\mathrm{NH}_4^+$$ / $$\mathrm{NH}_3$$

Question 7

Which of the following solutions is most acidic?

Accepted Answer

0.10 M HCl

Question 8

Which of the following salts will produce a basic solution when dissolved in water?

Accepted Answer

NaF

Question 9

Which of the following best describes a Lewis acid?

Accepted Answer

A substance that accepts a pair of electrons

Question 10

Which of the following weak bases has the highest base ionization constant ($$K_b) at 25$^\circC$$, according to Table 17.8?

Accepted Answer

Methylamine (CH$$_3NH$_2)$$

Question 11

A student mixes 1.0 M HCl and 1.0 M HF. Which acid will primarily determine the pH of the solution?

Accepted Answer

HCl, because it is a strong acid and will suppress the ionization of HF

Question 12

Which of the following statements about the relationship between $$K_a$$ and $$K_b$$ for a conjugate acid–base pair is correct?

Accepted Answer

$$K_a 	imes K_b = K_w$$

Question 13

Which of the following factors increases the strength of a binary acid HX?

Accepted Answer

Increasing electronegativity of X

Question 14

Which of the following statements is true regarding the percent ionization of a weak acid?

Accepted Answer

Percent ionization decreases as the initial concentration of the acid increases.

Question 15

A solution has $$[\mathrm{OH}^-] = 1 	imes 10$$^{-3}$$\ \mathrm{M}. $$What is the pOH of the solution?

Accepted Answer

$$3$$

Question 16

Which of the following is a property of bases?

Accepted Answer

Feel slippery

Question 17

Which of the following best describes why NaCl does not affect the pH of an aqueous solution?

Accepted Answer

Both Na$$^+$$ and Cl$$^-$$ are conjugates of strong acid/base and do not react with water.

Question 18

Which of the following acids is expected to have the highest $$K_a$$ value based on its structure?

Accepted Answer

An oxyacid with more oxygen atoms attached to the central atom

Question 19

Which of the following is a Lewis base?

Accepted Answer

NH$$_3$$

Acids and Bases: Properties, Strength, and Reactions

Study Guide - Practice Questions