Q: A solution has [H$$_3O$^+$$] = $$2.5 \times 10$$^{-5}$$ M. What is the pH of the solution?

$$pH = -\log(2.5 \times 10$$^{-5}$$) = 4.60$$

Q: Calculate the pOH of a solution with [OH$$^-$$] = $$3.2 \times 10$$^{-3}$$ M.

$$pOH = -\log(3.2 \times 10$$^{-3}$$) = 2.49$$

Q: A 0.10 M solution of a weak acid HA has a pH of 3.0. What is the value of $$K_a$$ for HA?

$$K_a = \frac{[H_3O^+][A^-]}{[HA]} = \frac{(1.0 \times 10$$^{-3}$$)^2$$}{0.10} = 1.0 \times $$10^{-5}$

Question 1

Which of the following best describes the Brønsted-Lowry definition of an acid?

Accepted Answer

A substance that donates a proton (H$$^+) to $$another substance.

Question 2

Which of the following is the conjugate base of HSO$$_4^-$$?

Accepted Answer

SO$$_4$$^{2-}$$

Question 3

A solution has [H$$_3O$^+$$] = $$2.5 	imes 10$$^{-5}$$ M. What is the pH of the solution?

Accepted Answer

$$pH = -\log(2.5 	imes 10$$^{-5}$$) = 4.60$$

Question 4

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

Accepted Answer

KCN

Question 5

Calculate the pOH of a solution with [OH$$^-$$] = $$3.2 	imes 10$$^{-3}$$ M.

Accepted Answer

$$pOH = -\log(3.2 	imes 10$$^{-3}$$) = 2.49$$

Question 6

Which of the following pairs is a conjugate acid-base pair?

Accepted Answer

H$$_2O $$and OH$$^-$$

Question 7

A 0.10 M solution of a weak acid HA has a pH of 3.0. What is the value of $$K_a$$ for HA?

Accepted Answer

$$K_a = \frac{[H_3O^+][A^-]}{[HA]} = \frac{(1.0 	imes 10$$^{-3}$$)^2$$}{0.10} = 1.0 	imes $$10^{-5}$

Question 8

Which of the following statements about the autoionization of water is correct?

Accepted Answer

The product $$[H_3O^+][OH^-] is $$constant at a given temperature.

Question 9

Which of the following is a Lewis acid?

Accepted Answer

BF$$_3$$

Question 10

A buffer solution is prepared by mixing 0.20 mol of acetic acid (CH$$_3$$COOH) and 0.20 mol of sodium acetate (CH$$_3$$COONa) in enough water to make 1.0 L of solution. What is the pH of the buffer? ($$K_a$$ for acetic acid = $$1.8 	imes 10$$^{-5}$$)

Accepted Answer

$$pH = pK_a + \log\left(\frac{[A^-]}{[HA]}\right) = 4.74$$

Question 11

Which of the following will increase the acidity of a solution?

Accepted Answer

Adding a strong acid.

Question 12

Which of the following best explains why HF is a weak acid while HCl is a strong acid?

Accepted Answer

HF has a much stronger H–F bond, making it less likely to ionize.

Question 13

Which of the following solutions has the lowest pH?

Accepted Answer

0.10 M HCl

Question 14

Which of the following is the correct net ionic equation for the reaction of HNO$$_3$$ with NaOH?

Accepted Answer

$$H^+ (aq) + OH^- (aq) \rightarrow H_2O (l)$$

Question 15

A solution is prepared by dissolving 0.10 mol of NH$$_4Cl in 1.0 L of $$water. Which of the following best describes the resulting solution?

Accepted Answer

The solution is acidic because NH$$_4^+$$ hydrolyzes to produce H$$^+.$$

Question 16

Which of the following is the strongest acid?

Accepted Answer

HClO$$_4$$

Question 17

Which of the following is a correct statement about buffer solutions?

Accepted Answer

They resist changes in pH when small amounts of acid or base are added.

Question 18

Which of the following is the correct expression for the ion-product constant for water ($$K_w) at 25$^\circC$$?

Accepted Answer

$$K_w = [H_3O^+][OH^-] = 1.0 	imes 10$$^{-14}$$

Question 19

Which of the following best describes the effect of increasing temperature on the value of $$K_w$$ for water?

Accepted Answer

$$K_w$$ increases as temperature increases.

Study Guide: Acid-Base Equilibria, Acids and Bases, and Related Concepts

Guida di studio - Domande di pratica

Study guide - Flashcard