Question 1

Which of the following best describes an Arrhenius acid?

Accepted Answer

A substance with H in its formula that dissociates to yield H3O+ in water.

Question 2

Which equation correctly represents the dissociation of a strong acid in water?

Accepted Answer

$$\mathrm{HA(g~or~l) + H_2O(l) \rightarrow H_3O^+(aq) + A^-(aq)}$$

Question 3

A 0.10 M solution of a weak acid HA has a $$K_a of$$ $$1.3 	imes 10$$^{-5}$$. What is the approximate concentration of $$[H_3O^+]$$ at equilibrium?

Accepted Answer

$$1.1 	imes 10$$^{-3}$$ M

Question 4

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

Accepted Answer

CH3COONa

Question 5

Which statement about the autoionization of water is correct?

Accepted Answer

It produces equal concentrations of $$H_3O^+$$ and $$OH^- in $$pure water.

Question 6

A solution has a pH of 2.62. What is the $$[H_3O^+]$$ concentration?

Accepted Answer

$$4.2 	imes 10$$^{-3}$$ M

Question 7

Which of the following is a Brønsted-Lowry base?

Accepted Answer

A species that accepts a proton.

Question 8

Which of the following is true about the relationship between $$K_a$$ and $$K_b$$ for a conjugate acid-base pair?

Accepted Answer

$$K_a 	imes K_b = K_w$$

Question 9

Which of the following is a Lewis acid?

Accepted Answer

BF3

Question 10

A solution of sodium acetate (NaAc) is prepared at 0.25 M. Given $$K_a$$ for acetic acid is $$1.8 	imes 10$$^{-5}$$, what is the expected pH of the solution?

Accepted Answer

pH \u003e 7

Question 11

Which of the following is NOT a strong acid?

Accepted Answer

HF

Question 12

Which of the following best explains why zinc reacts more rapidly with 1 M HCl than with 1 M CH3COOH?

Accepted Answer

HCl is a strong acid and produces a higher concentration of $$H_3O^+.$$

Question 13

Which of the following is a correct expression for the acid dissociation constant $$K_a$$ for the reaction $$HA(aq) + H_2O(l) \rightleftharpoons H_3O^+(aq) + A^-(aq)$$?

Accepted Answer

$$K_a = \dfrac{[H_3O^+][A^-]}{[HA]}$$

Question 14

Which of the following is true for a polyprotic acid?

Accepted Answer

The first dissociation step has the largest $$K_a$$ value.

Question 15

Which of the following ions will form an acidic solution when dissolved in water?

Accepted Answer

NH4+

Question 16

What is the percent dissociation of 0.035 M HClO if $$K_a = 2.9 	imes 10$$^{-8}$$?

Accepted Answer

0.091%

Question 17

Which of the following is a correct statement about the pH and pOH of a solution at 25°C?

Accepted Answer

$$\mathrm{pH + pOH = 14.00}$$

Question 18

Which of the following is a Lewis base in the reaction $$BF_3$$ + $$NH_3$$ \rightarrow F_3B-$$NH_3$$?

Accepted Answer

NH3

Question 19

Which of the following is a property of a strong base?

Accepted Answer

It is a water-soluble compound containing $$OH^-$$ ions.

Acid-Base Equilibria: Definitions, Strengths, and Reactions

Guida di studio - Domande di pratica

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