Exam Questions Acid-Base Equilibria Chapter.18

Chapter 18 Test Bank

Acid-Base Equilibria

1. The substance H₂SO₃ is considered

A. a weak Arrhenius base.

B. a strong Arrhenius acid.

C. a strong Arrhenius base.

D. a neutral compound.

E. a weak Arrhenius acid.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

2. The substance HOBr is considered

A. a weak Arrhenius acid.

B. a weak Arrhenius base.

C. a strong Arrhenius acid.

D. a strong Arrhenius base.

E. a neutral compound.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

3. The substance HCl is considered

A. a weak Arrhenius acid.

B. a weak Arrhenius base.

C. a strong Arrhenius acid.

D. a strong Arrhenius base.

E. a neutral compound.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

4. The substance Ba(OH)₂ is considered

A. a weak Arrhenius acid.

B. a weak Arrhenius base.

C. a strong Arrhenius acid.

D. a strong Arrhenius base.

E. a neutral compound.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

5. The substance Ca(OH)₂ is considered

A. a weak Arrhenius acid.

B. a weak Arrhenius base.

C. a strong Arrhenius acid.

D. a strong Arrhenius base.

E. a neutral compound.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

6. The substance NaNO₃ is considered

A. a weak Arrhenius acid.

B. a weak Arrhenius base.

C. a strong Arrhenius acid.

D. a strong Arrhenius base.

E. a neutral compound.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

7. Which, if any, of the following acids is strong?

A. phosphoric

B. carbonic

C. acetic

D. water

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Strengths

Topic: Acids and Bases

8. Which one of the following is a strong acid?

A. H₂CO₃

B. H₂SO₃

C. H₂SO₄

D. H₃PO₄

E. CH₃COOH

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Strengths

Topic: Acids and Bases

9. Which one of the following will give a solution with a pH > 7, but is not an Arrhenius base in the strict sense?

A. CH₃NH₂

B. NaOH

C. CO₂

D. Ca(OH)₂

E. CH₄

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

10. The substance NH₃ is considered

A. a weak acid.

B. a weak base.

C. a strong acid.

D. a strong base.

E. a neutral compound.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

11. The substance (CH₃CH₂)₂NH is considered

A. a weak acid.

B. a weak base.

C. a strong acid.

D. a strong base.

E. a neutral compound.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

12. The substance HClO₄ is considered

A. a weak acid.

B. a weak base.

C. a strong acid.

D. a strong base.

E. a neutral compound.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

13. Which of the following is the strongest acid?

A. CH₃COOH

B. HF

C. H₃PO₄

D. H₂SO₃

E. HI

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Easy

Gradable: automatic

Subtopic: Molecular Structure and Acid Strength (Nonmetal hydrides, Oxoacids)

Topic: Acids and Bases

14. Select the strongest acid from the following list.

A. HBrO

B. HBrO₂

C. HClO₂

D. HClO₃

E. HIO

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Molecular Structure and Acid Strength (Nonmetal hydrides, Oxoacids)

Topic: Acids and Bases

15. Select the strongest acid from the following list.

A. HBrO₄

B. HClO

C. HBrO₂

D. HBrO

E. HIO

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Molecular Structure and Acid Strength (Nonmetal hydrides, Oxoacids)

Topic: Acids and Bases

16. Which of the following is the strongest acid?

A. CH₃COOH

B. HF

C. H₃PO₄

D. H₂SO₃

E. H₂SO₄

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Easy

Gradable: automatic

Subtopic: Molecular Structure and Acid Strength (Nonmetal hydrides, Oxoacids)

Topic: Acids and Bases

17. Which of the following is the strongest base?

A. CH₃NH₂

B. NaNO₃

C. B(OH)₃

D. Al(OH)₃

E. LiOH

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Strengths

Topic: Acids and Bases

18. Which of the following pairs has the stronger acid listed first?

A. HBr, HI

B. HClO₂, HClO₃

C. H₂SeO₄, H₂SeO₃

D. HNO₂, HNO₃

E. HF, HCl

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Molecular Structure and Acid Strength (Nonmetal hydrides, Oxoacids)

Topic: Acids and Bases

19. Which of the following pairs has the stronger acid listed first?

A. H₂AsO₃, H₂AsO₄

B. HI, HBr

C. HClO, HClO₃

D. H₂S, HCl

E. H₂SO₃, H₂SO₄

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Molecular Structure and Acid Strength (Nonmetal hydrides, Oxoacids)

Topic: Acids and Bases

20. Given: H₂O(aq) + H₂O(l) H₃O⁺(aq) + OH^–(aq) ΔH°_rxn > 0

When the temperature of a sample of pure water is raised above 25°C,

A. the hydronium ion concentration will be greater than the hydroxide ion concentration.

B. the hydronium ion concentration will be less than the hydroxide ion concentration.

C. the value of K_w will increase.

D. the hydronium ion concentration could change to 1.0 × 10^–10 M.

E. the hydroxide ion concentration could change to 1.0 × 10^–10 M.

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Autoionization of Water (Kw)

Topic: Acids and Bases

21. Which of the following aqueous systems has the highest pH?

A. 0.1 M HA, pK_a = 11.89

B. 0.1 M HMO, pK_a = 8.23

C. 0.1 M HA, pK_a = 4.55

D. 0.1 M HBO, pK_a = 2.43

E. pure water

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Strengths

Topic: Acids and Bases

22. Which of the following acids has the lowest pH?

0.1 M HBO, pK_a = 2.43

0.1 M HA, pK_a = 4.55

0.1 M HMO, pK_a = 8.23

0.1 M HST, pK_a = 11.89

pure water

A. HA

B. HST

C. HMO

D. HBO

E. pure water

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Strengths

Topic: Acids and Bases

23. Which of the following liquids contains the strongest acid?

A. 0.1 M HA, pH = 6.85

B. 0.1 M HD, pH = 7.22

C. 0.1 M HE, pH = 8.34

D. 0.1 M HJ, pH = 11.88

E. pure water

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Strengths

Topic: Acids and Bases

24. What is the pH of a 0.20 M HCl solution?

A. < 0

B. 0.70

C. 1.61

D. 12.39

E. 13.30

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

25. What is the pH of a 0.75 M HNO₃ solution?

A. 0.12

B. 0.29

C. 0.63

D. 0.82

E. > 1.0

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

26. What is the pH of a 0.00200 M HClO₄ solution?

A. 0.995

B. 1.378

C. 2.699

D. 6.215

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

27. What is the pH of a 0.050 M HBr solution?

A. 0.89

B. 1.12

C. 1.30

D. 3.00

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

28. What is the pH of a 0.050 M LiOH solution?

A. < 1.0

B. 1.30

C. 3.00

D. 11.00

E. 12.70

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

29. What is the pH of a 0.0035 M KOH solution?

A. 2.46

B. 5.65

C. 8.35

D. 11.54

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

30. What is the pH of a 0.0125 M NaOH solution?

A. 0.972

B. 1.903

C. 12.097

D. 13.028

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

31. What is the pOH of a 0.0250 M HI solution?

A. 0.944

B. 1.602

C. 12.398

D. 13.056

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

32. What is the pOH of a 0.0085 M KOH solution?

A. 2.07

B. 4.77

C. 9.23

D. 11.93

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

33. What is the [OH–] for a solution at 25°C that has [H₃O⁺] = 2.35 × 10^–3 M?

A. 4.26 × 10^–5 M

B. 2.35 × 10^–11 M

C. 4.26 × 10^–12 M

D. 2.35 × 10^–17 M

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

34. What is the [OH^–] for a solution at 25°C that has [H₃O⁺] = 8.23 × 10^–2 M?

A. > 10^–5 M

B. 1.22 × 10^–6 M

C. 8.23 × 10^–12 M

D. 1.22 × 10^–13 M

E. 8.23 × 10^–16 M

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

35. What is the [OH^–] for a solution at 25°C that has pH = 4.29?

A. 1.4 × 10^–2 M

B. 5.l × 10^–5 M

C. 1.9 × 10^–10 M

D. 7.3 × 10^–13 M

E. 9.71 M

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

36. What is the [H₃O⁺] for a solution at 25°C that has pOH = 5.640?

A. 2.34 × 10^–4 M

B. 2.29 × 10^–6 M

C. 4.37 × 10^–9 M

D. 4.27 × 10^–11 M

E. 8.360 M

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

37. Select the correct relationship among the concentrations of species present in a 1.0 M aqueous solution of the weak acid represented by HA.

A. [H₂O] > [A^–] ~ [H₃O⁺] > [HA] > [OH^–]

B. [H₂O] > [HA] > [A^–] > [H₃O⁺] > [OH^–]

C. [HA] > [H₂O] > [A^–] > [H₃O⁺] > [OH^–]

D. [H₂O] > [HA] > [A^–] ~ [H₃O⁺] > [OH^–]

E. [HA] > [H₂O] > [A^–] ~ [H₃O⁺] > [OH^–]

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Hard

Gradable: automatic

Subtopic: Weak Acid Equilibrium (Ka)

Topic: Acids and Bases

38. The hydrated Al³⁺ ion, Al(H₂O)₆³⁺, is a weak acid in water. What are the products of its reaction with H₂O?

Al(H₂O)₆³⁺(aq) + H₂O(l) → ?

A. Al(H₂O)₅OH²⁺(aq) + H₃O⁺(aq)

B. Al(H₂O)₆H⁴⁺(aq) + OH^–(aq)

C. Al(H₂O)₅³⁺(aq) + 2H₂O(l)

D. Al(H₂O)₆OH²⁺(aq) + H₃O⁺(aq)

E. Al(H₂O)₆²⁺(aq) + H₃O⁺(aq)

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

39. When 14.7 mL of aqueous HBr (a strong acid) was added to water, 0.482 L of a solution with a pH of 4.23 was produced. What was the molarity of the original HBr solution?

A. 1.9 × 10^–3 M

B. 140 M

C. 0.288 M

D. 0.13 M

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

40. An aqueous solution is considered to be acidic if

A. the hydroxide ion concentration is 10^–6 M.

B. the hydrogen ion concentration is 10^–8 M.

C. the hydroxide and hydrogen ion concentrations are equal.

D. the hydroxide ion concentration is greater than the hydrogen ion concentration.

E. the hydroxide ion concentration is 10^–10 M.

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Easy

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

41. Select the pair of substances in that an acid is listed followed by its conjugate base.

A. H⁺, HCl

B. NH₃, NH₄+

C. HPO₄^2–, H₂PO^4–

D. HCO₃^–, CO₃^2–

E. CH₃COOH, CH₃COOH₂⁺

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

42. Select the pair of substances that is not a conjugate acid-base pair.

A. H₃O⁺, H₂O

B. HNO₂, NO₂^–

C. H₂SO₄, HSO₄^–

D. H₂S, S^2–

E. NH₃, NH₂^–

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

43. Which one of the following pairs is not a conjugate acid-base pair?

A. H₂O/OH^–

B. H₂O₂/HO₂^–

C. OH^–/O^2–

D. H₂PO₄^–/HPO₄^2–

E. HCl/H⁺

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

44. According to Brønsted and Lowry, which one of the following is not a conjugate acid-base pair?

A. H₃O⁺/OH^–

B. CH₃OH₂⁺/CH₃OH

C. HI/I^–

D. HSO₄^–/SO₄^2–

E. H₂/H^–

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

45. The acid dissociation constant K_a equals 1.26 × 10^–2 for HSO₄^– and is 5.6 × 10^–10 for NH₄. Which statement about the following equilibrium is correct?

HSO_4–(aq) + NH₃(aq) SO₄^2–(aq) + NH₄⁺(aq)

A. The reactants will be favored because ammonia is a stronger base than the sulfate anion.

B. The products will be favored because the hydrogen sulfate ion is a stronger acid than the ammonium ion.

C. Neither reactants nor products will be favored because all of the species are weak acids or bases.

D. The initial concentrations of the hydrogen sulfate ion and ammonia must be known before any prediction can be made.

E. This reaction is impossible to predict, since the strong acid and the weak base appear on the same side of the equation.

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Weak Acid Equilibrium (Ka)

Topic: Acids and Bases

46. A student adds 0.1 mol of oxalic acid and 0.1 mol of sodium dihydrogen phosphate to enough water to make 1.0 L of solution. The following equilibrium is established with the concentrations of the products greater than the concentrations of the reactants. Which of the statements about the equilibrium system is correct?

H₂C₂O₄(aq) + H₂PO₄(aq) HC₂O₄(aq) + H₃PO₄(aq)

A. Oxalic acid is a weaker acid than phosphoric acid.

B. The hydrogen oxalate anion, HC₂O₄, is a stronger base than the dihydrogen phosphate anion, H₂PO₄.

C. Phosphoric acid is a weaker acid than oxalic acid.

D. The dihydrogen phosphate anion, H₂PO₄^–, is a stronger acid than oxalic acid.

E. Water is a stronger acid than either oxalic or phosphoric acids.

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Strengths

Topic: Acids and Bases

47. Aqueous solutions of phosphoric acid and sodium nitrite are combined, and the following equilibrium is established.

H₃PO₄(aq) + NO₂(aq) H₂PO₄(aq) + HNO₂(aq)

The equilibrium constant K_c for this reaction is greater than one. Based on this information, which of the following statements is correct?

A. Phosphoric acid is a weaker acid than nitrous acid.

B. Nitrous acid is a weaker acid than water.

C. The nitrite anion is a weaker base than the dihydrogen phosphate anion.

D. The dihydrogen phosphate anion is a stronger acid than nitrous acid.

E. Phosphoric acid is a stronger acid than nitrous acid.

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Strengths

Topic: Acids and Bases

48. Butyric acid is responsible for the odor in rancid butter. A solution of 0.25 M butyric acid has a pH of 2.71. What is the K_a for the acid?

A. 0.36

B. 2.4 × 10^–2

C. 7.8 × 10^–3

D. 1.5 × 10^–5

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Weak Acid Equilibrium (Ka)

Topic: Acids and Bases

49. A 0.15 M solution of chloroacetic acid has a pH of 1.86. What is the value of K_a for this acid?

A. 7.2 × 10¹

B. 0.16

C. 0.099

D. 0.0014

E. 0.00027

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Weak Acid Equilibrium (Ka)

Topic: Acids and Bases

50. A 0.050 M solution of the weak acid HA has [H₃O⁺] = 3.77 × 10^–4 M. What is the K_a for the acid?

A. 7.5 × 10^–3 M

B. 2.8 × 10^–6 M

C. 7.0 × 10^–7 M

D. 7.0 × 10^–8 M

E. 2.6 × 10^–11 M

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Weak Acid Equilibrium (Ka)

Topic: Acids and Bases

51. Formic acid, which is a component of insect venom, has a K_a = 1.8 × 10^–4. What is the [H₃O⁺] in a solution that is initially 0.10 M formic acid, HCOOH?

A. 4.2 × 10^–3 M

B. 8.4 × 10^–3 M

C 1.8 × 10^–4 M

D. 1.8 × 10^–5 M

E. 1.8 × 10^–6 M

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Weak Acid Equilibrium (Ka)

Topic: Acids and Bases

52. Picric acid has been used in the leather industry and in etching copper. However, its laboratory use has been restricted because it dehydrates on standing and can become shock sensitive. It has an acid dissociation constant of 0.42. What is the [H₃O⁺] for a 0.20 M solution of picric acid?

A. 0.022 M

B. 0.052 M

C. 0.15 M

D. 0.29 M

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Weak Acid Equilibrium (Ka)

Topic: Acids and Bases

53. Lactic acid has a pK_a of 3.08. What is the approximate degree of dissociation of a 0.35 M solution of lactic acid?

A. 1.1%

B. 2.2%

C. 4.8%

D. 14%

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Weak Acid Equilibrium (Ka)

Topic: Acids and Bases

54. A 1.25 M solution of the weak acid HA is 9.2% dissociated. What is the pH of the solution?

A. 0.64

B. 0.94

C. 1.13

D. 2.16

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Weak Acid Equilibrium (Ka)

Topic: Acids and Bases

55. Phosphoric acid, H₃PO₄, is a triprotic acid, for which K_a1 = 7.2 × 10^–3, K_a2 = 6.3 × 10^–8 and K_a3 = 4.2 × 10^–13. What is the value of K_b for the hydrogen phosphate anion, HPO₄?

A. 6.3 × 10^–8

B. 4.2 × 10^–13

C. 1.4 × 10^–12

D. 1.6 × 10^–7

E. 2.4 × 10^–2

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Polyprotic Acids

Topic: Acids and Bases

56. Farmers who raise cotton once used arsenic acid, H₃AsO₄, as a defoliant at harvest time. Arsenic acid is a polyprotic acid with K₁ = 2.5 × 10^–4, K₂ = 5.6 × 10^–8, and K₃ = 3 × 10^–13. What is the pH of a 0.500 M solution of arsenic acid?

A. 0.85

B. 1.96

C. 3.90

D. 4.51

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Polyprotic Acids

Topic: Acids and Bases

57. Arsenic acid, H₃AsO₄, is used industrially to manufacture insecticides. Arsenic acid is a polyprotic acid with K₁ = 2.5 × 10^–4, K₂ = 5.6 × 10^–8, and K₃ = 3 × 10^–13. What is the concentration of the HAsO₄^2– in a solution whose initial arsenic acid concentration was 0.35 M?

A. 9.4 × 10^–3 M

B. 2.5 × 10^–4 M

C. 8.8 × 10^–5 M

D. 5.6 × 10^–8 M

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Polyprotic Acids

Topic: Acids and Bases

58. What is the pH of a 0.050 M triethylamine, (C₂H₅)₃N, solution?

K_b for triethylamine is 5.3 × 10^–4.

A. 11.69

B. 8.68

C. 5.32

D. 2.31

E. < 2.0

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Weak Base Equilibrium (Kb)

Topic: Acids and Bases

59. Hydroxylamine, HONH₂, readily forms salts such as hydroxylamine hydrochloride which are used as antioxidants in soaps. Hydroxylamine has K_b of 9.1 × 10^–9. What is the pH of a 0.025 M HONH₂ solution?

A. 2.90

B. 4.82

C. 9.18

D. 9.91

E. 11.10

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Weak Base Equilibrium (Kb)

Topic: Acids and Bases

60. What is the value of K_b for the formate anion, HCOO^–? K_a(HCOOH) = 2.1 × 10^–4

A. _–2.1 × 10^–4

B. 2.1 × 10^–4

C. 6.9 × 10^–6

D. 4.8 × 10^–11

E. 2.1 × 10^–18

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: Weak Base Equilibrium (Kb)

Topic: Acids and Bases

61. What is the value of K_b for the cyanide anion, CN–? _Ka(HCN) = 6.2 × 10^–10

A. 1.6 × 10^–4

B 1.6 × 10^–5

C. 3.8 × 10^–4

D. 3.8 × 10^–5

E. 6.2 × 10⁴

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: Weak Base Equilibrium (Kb)

Topic: Acids and Bases

62. What is the value of K_a for the methylammonium ion, CH₃NH₃⁺? K_b(CH₃NH₂) = 4.4 × 10^–4

A. 4.4 × 10^–4

B. 4.8 × 10_–6

C. 4.4 × 10^–10

D 2.3 × 10^–11

E. 4.4 × 10^–18

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: Weak Base Equilibrium (Kb)

Topic: Acids and Bases

63. What is the pH of a 0.0100 M sodium benzoate solution? K_b (C₇H₅O₂) = 1.5 × 10^–10

A. 0.38

B. 5.91

C. 8.09

D. 9.82

E. 13.62

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Weak Base Equilibrium (Kb)

Topic: Acids and Bases

64. What is the pH of a 0.010 M triethanolammonium chloride, (HOC₂H₂)₃NHCl, solution?

K_b, ((HOC₂H₂)₃N) = 5.9 × 10^–7

A. 2.75

B. 4.89

C. 9.11

D. 11.25

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Weak Base Equilibrium (Kb)

Topic: Acids and Bases

65. Which of the following aqueous liquids will have the highest pH?

A. 0.1 M CH₃COOH, pK_a = 4.7

B. 0.1 M CuCl₂, pK_a = 7.5

C. 0.1 M H₃C₆H₅O₇, pK_a = 3.1

D. 0.1 M ZnCl₂, pK_a = 9.0

E. pure water

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

66. Which of the following aqueous liquids is the most acidic?

A. 0.1 M Al(NO₃)₃, K_a = 1 × 10^–5

B. 0.1 M Be(NO₃)₂, K_a = 4 × 10^–6

C. 0.1 M Pb(NO₃)₂, K_a = 3 × 10^–8

D. 0.1 M Ni(NO₃)₂, K_a = 1 × 10^–10

E. pure water

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

67. A solution is prepared by adding 0.10 mol of sodium fluoride, NaF, to 1.00 L of water. Which statement about the solution is correct?

A. The solution is basic.

B. The solution is neutral.

C. The solution is acidic.

D. The concentrations of fluoride ions and sodium ions will be identical.

E. The concentration of fluoride ions will be greater than the concentration of sodium ions.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

68. A solution is prepared by adding 0.10 mol of potassium acetate, KCH₃COO, to 1.00 L of water.

Which statement about the solution is correct?

A. The solution is basic.

B. The solution is neutral.

C. The solution is acidic.

D. The concentrations of potassium ions and acetate ions will be identical.

E. The concentration of acetate ions will be greater than the concentration of potassium ions.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

69. A solution is prepared by adding 0.10 mol of sodium sulfide, Na₂S, to 1.00 L of water. Which statement about the solution is correct?

A. The solution is basic.

B. The solution is neutral.

C. The solution is acidic.

D. The concentration of sodium ions and sulfide ions will be identical.

E. The concentration of sulfide ions will be greater than the concentration of sodium ions.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

70. A solution is prepared by adding 0.10 mol of iron(III) nitrate, Fe(NO₃)₃, to 1.00 L of water. Which statement about the solution is correct?

A. The solution is basic.

B. The solution is neutral.

C. The solution is acidic.

D. The value of K_a for the species in solution must be known before a prediction can be made.

E. The value of K_b for the species in solution must be known before a prediction can be made.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

71. Ammonium chloride is used as an electrolyte in dry cells. Which of the following statements about a 0.10 M solution of NH₄Cl, is correct?

A. The solution is weakly basic.

B. The solution is strongly basic.

C. The solution is neutral.

D. The solution is acidic.

E.The values for K_a and K_b for the species in solution must be known before a prediction can be made.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

72. A solution is prepared by adding 0.10 mol of lithium nitrate, LiNO₃, to 1.00 L of water. Which statement about the solution is correct?

A. The solution is basic.

B. The solution is neutral.

C. The solution is weakly acidic.

D. The solution is strongly acidic.

E. The values for K_a and K_b for the species in solution must be known before a prediction can be made.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

73. A solution is prepared by adding 0.10 mol of potassium chloride, KCl, to 1.00 L of water. Which statement about the solution is correct?

A. The solution is basic.

B. The solution is neutral.

C. The solution is acidic.

D. One needs to know the temperature before any of these predictions can be made.

E. The values for K_a and K_b for the species in solution must be known before a prediction can be made.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

74. An aqueous solution is prepared by dissolving the salt formed by the neutralization of a weak acid by a weak base. Which statement about the solution is correct?

A. The solution is strongly basic.

B. The solution is weakly basic.

C. The solution is neutral.

D. The solution is acidic.

E. The values for K_a and K_b for the species in solution must be known before a prediction can be made.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

75. Which one of the following substances will give an aqueous solution of pH < 7?

A. KI

B NH₄Br

C. Na₂CO₃

D. CH₃COONa

E. CH₃OH

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

76. Which one of the following substances will give an aqueous solution of pH closest to 7?

A. KNO₃

B. CO₂

C. NH₄I

D. NH₃

E. CH₃NH₂

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

77. Which of the following is considered a Lewis acid?

A. CH₃NH₂

B. BCl₃

C. F^–

D. BF₄^–

E. CH₄

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Lewis Acids and Bases

Topic: Acids and Bases

78. Which of the following is a Lewis base?

A. BCl₃

B. Cu²⁺

C. Cl^–

D. Mn²⁺

E. NH₄⁺

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Lewis Acids and Bases

Topic: Acids and Bases

79. Iodine trichloride, ICl₃, will react with a chloride ion to form ICl₄^–. Which species, if any, acts as a Lewis acid this reaction?

A. ICl₄^–

B ICl₃

C. Cl^–

D. the solvent

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Lewis Acids and Bases

Topic: Acids and Bases

80. Calcium oxide, CaO, also known as quick lime, will react with carbon dioxide to form calcium carbonate, CaCO₃. Which species, if any, acts as a Lewis acid in the reaction?

A. Ca²⁺

B. O^2–

C. CO₂

D. CaCO₃

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Lewis Acids and Bases

Topic: Acids and Bases

81. Which one of the following is a Lewis acid but not a Brønsted-Lowry acid?

A. Fe₃⁺

B. H₃O⁺

C. HSO₄^–

D. NH₃

E. H₂O

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Lewis Acids and Bases

Topic: Acids and Bases

82. Arrhenius bases raise the hydroxide ion concentration when dissolved in water.

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

83. It is not possible to have a pH lying outside the range 0 to 14.

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Medium

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

84. K_w = 1.0 × 10^–14, regardless of temperature.

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Medium

Gradable: automatic

Subtopic: Autoionization of Water (Kw)

Topic: Acids and Bases

85. If a strong acid such as HCl is diluted sufficiently with water, the pH will be higher than 7.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: pH Scale

Topic: Acids and Bases

86. All Brønsted-Lowry bases contain the hydroxide ion, OH^–.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

87. All Brønsted-Lowry bases have at least one lone pair of electrons.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

88. In order to be a Brønsted-Lowry base, a species must contain a proton.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

89. All strong acids have weak conjugate bases.

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

90. If the compound HX is a strong acid (where H is the acidic proton in this acid), then the ion X^– is a weak base.

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

91. The ammonium ion, NH₄⁺, is a weak acid.

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

92. Hydrated metal ions in aqueous solution can act as Brønsted-Lowry acids.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

93. A solution of sodium acetate (CH₃COONa) in water is weakly basic.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions)

Topic: Acids and Bases

94. The strongest base which can exist in water is the hydroxide ion.

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Strengths

Topic: Acids and Bases

95. All Lewis acids contain at least one proton.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Lewis Acids and Bases

Topic: Acids and Bases

96. The chloride ion, Cl^–, is a typical Lewis acid.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Lewis Acids and Bases

Topic: Acids and Bases

97. In applying molecular orbital theory, the bond order is calculated in the same way as with Lewis structures.

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Medium

Gradable: automatic

Subtopic: Molecular Orbital (MO) Theory

Topic: Covalent Bond Theories

98. All weak acids have strong conjugate bases.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Hard

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

99. Which of the following is not a characteristic property of bases?

A. taste bitter

B. turn litmus from pink to blue

C. neutralize acids

D. react with carbonates to produce carbon dioxide gas

E. feel slippery

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Definitions

Topic: Acids and Bases

100. Which, if any, of the following is an example of the leveling effect?

A. The concentrations of H⁺ and OH^- in pure water are equal.

B. The number of strong acids equals the number of strong bases.

C. The number of strong acids equals the number of weak acids.

D. In water, no acid stronger than H₃O⁺ can exist.

E. None of these are examples of the leveling effect.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Strengths

Topic: Acids and Bases

Category # of Questions

Accessibility: Keyboard Navigation 96

Bloom's: 1. Remember 15

Bloom's: 2. Understand 39

Bloom's: 3. Apply 46

Difficulty: Easy 26

Difficulty: Hard 9

Difficulty: Medium 63

Difficulty: Hard 1

Difficulty: Medium 1

Gradable: automatic 100

Subtopic: Acid-Base Definitions 23

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions) 15

Subtopic: Acid-Base Strengths 10

Subtopic: Autoionization of Water (Kw) 2

Subtopic: Lewis Acids and Bases 7

Subtopic: Molecular Orbital (MO) Theory 1

Subtopic: Molecular Structure and Acid Strength (Nonmetal hydrides, Oxoacids) 6

Subtopic: pH Scale 17

Subtopic: Polyprotic Acids 3

Subtopic: Weak Acid Equilibrium (Ka) 9

Subtopic: Weak Base Equilibrium (Kb) 7

Topic: Acids and Bases 1

Topic: Acids and Bases 98

Topic: Covalent Bond Theories 1