Q: A solution has $$[H_3O^+] = 2.0 \times 10$$^{-5}$$\ \mathrm{M}. $$What is the pH of the solution?

$$\mathrm{pH} = -\log(2.0 \times 10$$^{-5}$$) = 4.70$$

Q: A student titrates 25.0 mL of HCl with 0.100 M NaOH. It takes 30.0 mL of NaOH to reach the equivalence point. What is the concentration of the HCl solution?

$$\mathrm{M_{HCl} = \frac{(0.100\ M) \times (30.0\ mL)}{25.0\ mL} = 0.120\ M}$$

Q: What is the $$[OH^-] in a $$solution where $$[H_3O^+] = 1.0 \times 10$$^{-9}$$\ \mathrm{M} at 25$$°C?

$$[OH^-] = \frac{1.0 \times 10$$^{-14}$$}{1.0 \times 10$$^{-9}$$} = 1.0 \times 10$$^{-5}$$\ \mathrm{M}$$

Question 1

Which of the following statements best describes the difference between a strong acid and a weak acid in aqueous solution?

Accepted Answer

A strong acid completely ionizes in solution, while a weak acid only partially ionizes.

Question 2

Which of the following is the correct balanced equation for the neutralization reaction between sulfuric acid and sodium hydroxide?

Accepted Answer

$$\mathrm{H_2SO_4\ (aq) + 2\ NaOH\ (aq) \rightarrow Na_2SO_4\ (aq) + 2\ H_2O\ (l)}$$

Question 3

A solution has $$[H_3O^+] = 2.0 	imes 10$$^{-5}$$\ \mathrm{M}. $$What is the pH of the solution?

Accepted Answer

$$\mathrm{pH} = -\log(2.0 	imes 10$$^{-5}$$) = 4.70$$

Question 4

Which of the following compounds is a strong base?

Accepted Answer

Potassium hydroxide, $$\mathrm{KOH}$$

Question 5

Which of the following best describes the role of water in the reaction $$\mathrm{NH_3$ + H_2O \rightarrow NH_4$^+ + OH^-}$$ according to the Brønsted–Lowry definition?

Accepted Answer

Water acts as a Brønsted–Lowry acid because it donates a proton to ammonia.

Question 6

A student titrates 25.0 mL of HCl with 0.100 M NaOH. It takes 30.0 mL of NaOH to reach the equivalence point. What is the concentration of the HCl solution?

Accepted Answer

$$\mathrm{M_{HCl} = \frac{(0.100\ M) 	imes (30.0\ mL)}{25.0\ mL} = 0.120\ M}$$

Question 7

Which of the following is the correct net ionic equation for the neutralization of a strong acid with a strong base?

Accepted Answer

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

Question 8

Which of the following statements about buffers is correct?

Accepted Answer

A buffer contains significant amounts of a weak acid and its conjugate base, allowing it to resist changes in pH.

Question 9

What is the $$[OH^-] in a $$solution where $$[H_3O^+] = 1.0 	imes 10$$^{-9}$$\ \mathrm{M} at 25$$°C?

Accepted Answer

$$[OH^-] = \frac{1.0 	imes 10$$^{-14}$$}{1.0 	imes 10$$^{-9}$$} = 1.0 	imes 10$$^{-5}$$\ \mathrm{M}$$

Question 10

Which of the following is NOT a property of acids?

Accepted Answer

Acids turn red litmus paper blue.

Question 11

Which of the following is the correct name for $$\mathrm{H_2SO_3}$$?

Accepted Answer

Sulfurous acid

Question 12

A solution has a pH of 3.2. What is the $$[H_3O^+]$$?

Accepted Answer

$$[H_3O^+] = 10$$^{-3.2}$$ = 6.3 	imes 10$$^{-4}$$\ \mathrm{M}$$

Question 13

Which of the following best describes why sodium hydroxide is considered a strong base?

Accepted Answer

It completely dissociates into $$\mathrm{Na^+}$$ and $$\mathrm{OH^-}$$ ions in aqueous solution.

Question 14

Which of the following is an example of an amphoteric substance?

Accepted Answer

Water, $$\mathrm{H_2O}$$

Question 15

Which of the following reactions represents the reaction of an acid with a metal oxide?

Accepted Answer

$$\mathrm{2\ HCl\ (aq) + K_2O\ (s) \rightarrow 2\ KCl\ (aq) + H_2O\ (l)}$$

Question 16

Which of the following is the correct formula for the ion product constant for water ($$K_w) at 25$$°C?

Accepted Answer

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

Question 17

Which of the following best explains why acid rain is damaging to marble statues and buildings?

Accepted Answer

Acids react with metal oxides in marble, producing water and soluble salts that wash away.

Question 18

Which of the following is the conjugate base of $$\mathrm{H_2SO_4}$$?

Accepted Answer

$$\mathrm{$$HSO_4$$^-}$$

Chapter 14: Acids and Bases – General Chemistry Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard