Q: Which of the following is true for a neutral solution at 25°C?

$[H^+] = [OH^-] = 1 \times 10^{-7}$ M

Q: Which of the following statements about the pH scale is correct?

A solution with pH = 7 is neutral

Q: Which of the following is the correct formula for calculating percent dissociation of an acid?

$\% \text{ dissociation} = \dfrac{\text{amount dissociated (mol/L)}}{\text{total amount of HA (mol/L)}} \times 100$

Q: Which of the following is NOT a correct definition of a base?

A $H^+$ (proton) donor (Bronsted-Lowry)

Q: If the $K_a$ of $CH_3COOH$ is $1.8 \times 10^{-5}$ and the $K_a$ of $HF$ is $7.2 \times 10^{-4}$, what is the equilibrium constant $K$ for the reaction $CH_3COOH + F^- \rightleftharpoons HF + CH_3COO^-$?

$K = \dfrac{7.2 \times 10^{-4}}{1.8 \times 10^{-5}}$

Question 1

Which of the following best describes a Lewis acid?

Accepted Answer

A lone-pair acceptor

Question 2

Given the reaction $HA + H_2O \rightleftharpoons A^- + H_3O^+$, which species is the conjugate base?

Accepted Answer

$A^-$

Question 3

What is the equilibrium constant expression for the dissociation of a generic acid $HA$ in water?

Accepted Answer

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

Question 4

Which statement is true regarding acid strength and $K_a$?

Accepted Answer

A strong acid has a $K_a$ much greater than 1

Question 5

Which of the following acids is the strongest based on the $K_a$ values below?

$HCl$: very large
$HF$: $7.2 	imes 10^{-4}$
$CH_3COOH$: $1.8 	imes 10^{-5}$
$H_2CO_3$: $4.3 	imes 10^{-7}$

Accepted Answer

$HCl$

Question 6

If $HA$ is a stronger acid than $H_3O^+$, what is the value of $K_a$ for $HA$?

Accepted Answer

$K_a > 1$

Question 7

What is the value of the equilibrium constant $K$ for the auto-ionization of water at 25°C?

Accepted Answer

$K < 1$

Question 8

At 25°C, what is the value of $K_w$ for water?

Accepted Answer

$K_w = 1 	imes 10^{-14}$

Question 9

What is the pH of a solution with $[H^+] = 1.0 	imes 10^{-5}$ M?

Accepted Answer

pH = 5

Question 10

A solution has a pH of 3. What is the $[H^+]$ concentration?

Accepted Answer

$[H^+] = 1 	imes 10^{-3}$ M

Question 11

Which of the following is true for a neutral solution at 25°C?

Accepted Answer

$[H^+] = [OH^-] = 1 	imes 10^{-7}$ M

Question 12

Which of the following statements about the pH scale is correct?

Accepted Answer

A solution with pH = 7 is neutral

Question 13

A 0.10 M solution of HCl is prepared. What is the pH?

Accepted Answer

pH = 1

Question 14

A 0.10 M solution of CH$_3$COOH (acetic acid) has $K_a = 1.8 	imes 10^{-5}$. Which type of problem is this?

Accepted Answer

Equilibrium problem

Question 15

Which of the following is the correct formula for calculating percent dissociation of an acid?

Accepted Answer

$\% 	ext{ dissociation} = \dfrac{	ext{amount dissociated (mol/L)}}{	ext{total amount of HA (mol/L)}} 	imes 100$

Question 16

Which of the following is NOT a correct definition of a base?

Accepted Answer

A $H^+$ (proton) donor (Bronsted-Lowry)

Question 17

Which of the following 0.1 M solutions will be neutral?

Accepted Answer

NaCl

Question 18

Which of the following 0.1 M solutions has the highest pH?

Accepted Answer

KCN

Question 19

If the $K_a$ of $CH_3COOH$ is $1.8 	imes 10^{-5}$ and the $K_a$ of $HF$ is $7.2 	imes 10^{-4}$, what is the equilibrium constant $K$ for the reaction $CH_3COOH + F^- ightleftharpoons HF + CH_3COO^-$?

Accepted Answer

$K = \dfrac{7.2 	imes 10^{-4}}{1.8 	imes 10^{-5}}$

Chapter 17: Acids & Bases – General Chemistry Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards