Ch.19 Ionic Equilibria In Aqueous Systems Test Bank Docx

Chapter 19 Test Bank

Ionic Equilibria in Aqueous Systems

1. Which of the following aqueous mixtures would be a buffer system?

A. HCl, NaCl

B. HNO₃, NaNO₃

C. H₃PO₄, H₂PO₄^–

D. H₂SO₄, CH₃COOH

E. NH₃, NaOH

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Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

2. Which, if any, of the following aqueous mixtures would be a buffer system?

A. CH₃COOH, NaH₂PO₄

B. H₂CO₃, HCO₃^–

C. H₂PO₄^–, HCO₃^–

D. HSO₄^–, HSO₃^–

E. None of these choices are correct.

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Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

3. Equal volumes of the following pairs of solutions are mixed. Which pair will produce a buffer solution?

A. 0.10 mol L^–1 HCl and 0.05 mol L^–1 NaOH

B. 0.10 mol L^–1 HCl and 0.15 mol L^–1 NH₃

C. 0.10 mol L^–1 HCl and 0.05 mol L^–1 NH₃

D. 0.10 mol L^–1 HCl and 0.20 mol L^–1 CH₃COOH

E. 0.10 mol L^–1 HCl and 0.20 mol L^–1 NaCl

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

4. Which one of the following aqueous solutions, when mixed with an equal volume of 0.10 mol L^–1 aqueous NH₃, will produce a buffer solution?

A. 0.10 mol L^–1 HCl

B. 0.20 mol L^–1 HCl

C. 0.10 mol L^–1 CH³COOH

D. 0.050 mol L^–1 NaOH

E. 0.20 mol L^–1 NH₄Cl

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Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

5. Which one of the following pairs of 0.100 mol L^–1 solutions, when mixed, will produce a buffer solution?

A. 50. mL of aqueous CH₃COOH and 25. mL of aqueous HCl

B. 50. mL of aqueous CH₃COOH and 100. mL of aqueous NaOH

C. 50. mL of aqueous NaOH and 25. mL of aqueous HCl

D. 50. mL of aqueous CH₃COONa and 25. mL of aqueous NaOH

E. 50. mL of aqueous CH₃COOH and 25. mL of aqueous CH₃COONa

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

6. Which of the following has the highest buffer capacity?

A. 0.10 M H₂PO₄^–/0.10 M HPO₄^2–

B. 0.50 M H₂PO₄^–/0.10 M HPO₄^2–

C. 0.10 M H₂PO₄^–/0.50 M HPO₄^2–

D. 0.50 M H₂PO₄^–/0.50 M HPO₄^2–

E. They all have the same buffer capacity.

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Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

7. A popular buffer solution consists of carbonate (CO₃^2–) and hydrogen carbonate (HCO₃^–) conjugate acid-base pair. Which, if any, of the following such buffers has the highest buffer capacity?

A. 0.9 M CO₃^2– and 0.1 M HCO₃^–

B. 0.1 M CO₃^2– and 0.9 M HCO₃^–

C. 0.5 M CO₃^2– and 0.5 M HCO₃^–

D. 0.1 M CO₃^2– and 0.1 M HCO₃^–

E. They all have the same buffer capacity.

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Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

8. A popular buffer solution consists of carbonate (CO₃^2–) and hydrogen carbonate (HCO₃^–) conjugate acid-base pair. Which, if any, of the following such buffers can neutralize the greatest amount of added hydrochloric acid, while remaining within its buffer range?

A. 1 L of 0.9 M CO₃^2– and 0.1 M HCO₃^–

B. 1 L of 0.1 M CO₃^2– and 0.9 M HCO₃^–

C. 1 L of 0.5 M CO₃^2– and 0.5 M HCO₃^–

D. 1 L of 0.1 M CO₃^2– and 0.1 M HCO₃^–

E. They can all neutralize the same amount of hydrochloric acid.

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

9. Which of the following acids should be used to prepare a buffer with a pH of 4.5?

A. HOC₆H₄OCOOH, K_a = 1.0 × 10^–3

B. C₆H₄(COOH)₂, K_a = 2.9 × 10^–4

C. CH₃COOH, K_a = 1.8 × 10^–5

D. C₅H₅O₅COOH, K_a = 4.0 × 10^–6

E. HBrO, K_a = 2.3 × 10^–9

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Bloom's: 2. Understand

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Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

10. Citric acid has an acid dissociation constant of 8.4 × 10^–4. It would be most effective for preparation of a buffer with a pH of

A. 2.

B. 3.

C. 4.

D. 5.

E. 6.

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

11. A buffer is to be prepared by adding solid sodium acetate to 0.10 M CH₃COOH. Which of the following concentrations of sodium acetate will produce the most effective buffer?

A. 3.0 M CH₃COONa

B. 2.5 M CH₃COONa

C. 2.0 M CH₃COONa

D. 1.5 M CH₃COONa

E. 0.30 M CH₃COONa

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

12. An acetate buffer has a pH of 4.40. Which of the following changes will cause the pH to decrease?

A. dissolving a small amount of solid sodium acetate

B. adding a small amount of dilute hydrochloric acid

C. adding a small amount of dilute sodium hydroxide

D. dissolving a small amount of solid sodium chloride

E. diluting the buffer solution with water

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Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

13. A phosphate buffer (H₂PO₄^–/HPO₄^2-) has a pH of 8.3. Which of the following changes will cause the pH to increase?

A. dissolving a small amount of Na₂HPO₄

B. dissolving a small amount of NaH₂PO₄

C. adding a small amount of dilute hydrochloric acid

D. adding a small amount of dilute phosphoric acid

E. making the buffer more concentrated by removing some water

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Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

14. What will be the effect of adding 0.5 mL of 0.1 M NaOH to 100 mL of an acetate buffer in which [CH₃COOH] = [CH₃COO^–] = 0.5 M?

A. The pH will increase slightly.

B. The pH will increase significantly.

C. The pH will decrease slightly.

D. The pH will decrease significantly.

E. Since it is a buffer solution, the pH will not be affected.

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Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

15. What will be the effect of adding 0.5 mL of 0.1 M HCl to 100 mL of a phosphate buffer in which [H₂PO₄^–] = [HPO₄^2–] = 0.35 M?

A. The pH will increase slightly.

B. The pH will increase significantly.

C. The pH will decrease slightly.

D. The pH will decrease significantly.

E. Since it is a buffer solution, the pH will not be affected.

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Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

16. Buffer solutions with the component concentrations shown below were prepared. Which of them should have the lowest pH?

A. [CH₃COOH] = 0.25 M, [CH₃COO^–] = 0.25 M

B. [CH₃COOH] = 0.75 M, [CH₃COO^–] = 0.75 M

C. [CH₃COOH] = 0.75 M, [CH₃COO^–] = 0.25 M

D. [CH₃COOH] = 0.25 M, [CH₃COO^–] = 0.75 M

E. [CH₃COOH] = 1.00 M, [CH₃COO^–] = 1.00 M

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

17. Buffer solutions with the component concentrations shown below were prepared. Which of them should have the highest pH?

A. [H₂PO₄^–] = 0.50 M, [HPO₄^2–] = 0.50 M

B. [H₂PO₄^–] = 1.0 M, [HPO₄^2–] = 1.0 M

C. [H₂PO₄^–] = 1.0 M, [HPO₄^2–] = 0.50 M

D. [H₂PO₄^–] = 0.50 M, [HPO₄^2–] = 1.0 M

E. [H₂PO₄^–] = 0.75 M, [HPO₄^2–] = 1.0 M

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

18. A buffer is prepared by adding 0.5 mol of solid sodium hydroxide to 1.0 L of 1.0 M acetic acid (CH³COOH). What is the pH of the buffer?

A. The pH will be pK_a – 0.30, where pK_a is that of acetic acid.

B. The pH will be greater than the pK_a for acetic acid.

C. The pH will be less than the value in answer a.

D. The pH will be equal to the pK_a for acetic acid.

E. More information is needed to solve the problem.

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

19. A solution is prepared by adding 100 mL of 0.2 M hydrochloric acid to 100 mL of 0.4 M sodium formate. Is this a buffer solution, and if so, what is its pH?

A. It is a buffer, pH > pK_a of formic acid.

B. It is a buffer, pH < pK_a of formic acid.

C. It is a buffer, pH = pK_a of formic acid.

D. It is a buffer, pH = pK_b of sodium formate.

E. Since hydrochloric acid is a strong acid, this is not a buffer.

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

20. A buffer is prepared by adding 100 mL of 0.50 M sodium hydroxide to 100 mL of 0.75 M propanoic acid. Is this a buffer solution, and if so, what is its pH?

A. It is a buffer, pH > pK_a of propanoic acid.

B. It is a buffer, pH < pK_a of propanoic acid.

C. It is a buffer, pH = pK_a of propanoic acid.

D. It is a buffer, pH = pK_b of sodium propanoate.

E. Since sodium hydroxide is a strong base, this is not a buffer.

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

21. A solution is prepared by adding 500 mL of 0.3 M NaClO to 500 mL of 0.4 M HClO. What is the pH of this solution?

A. The pH will be greater than the pK_a of hypochlorous acid.

B. The pH will be less than the pK_a of hypochlorous acid.

C. The pH will be equal to the pK_a of hypochlorous acid.

D. The pH will equal the pK_b of sodium hypochlorite.

E. None of these choices are correct.

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

22. What is the pH of a buffer that consists of 0.45 M CH₃COOH and 0.35 M CH₃COONa?

K_a = 1.8 × 10^–5

A. 4.49

B. 4.64

C. 4.85

D. 5.00

E. 5.52

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

23. What is the pH of a solution that consists of 0.50 M H₂C₆H₆O₆ (ascorbic acid) and 0.75 M NaHC₆H₆O₆ (sodium ascorbate)? For ascorbic acid, K_a = 6.8 × 10^–5

A. 3.76

B. 3.99

C. 4.34

D. 4.57

E. 5.66

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

24. What is the pH of a buffer that consists of 0.20 M NaH₂PO₄ and 0.40 M Na₂HPO₄?

For NaH₂PO₄, Ka = 6.2 × 10^–8

A. 6.51

B. 6.91

C. 7.51

D. 7.90

E. 8.13

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Bloom's: 3. Apply

Difficulty: Medium

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Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

25. What is the [H₃O⁺] in a buffer that consists of 0.30 M HCOOH and 0.20 M HCOONa?

For HCOOH, K_a = 1.7 × 10^–4

A. 1.1 × 10^–4 M

B. 2.6 × 10^–4 M

C. 4.3 × 10^–4 M

D. 6.7 × 10^–5 M

E. None of these choices are correct.

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

26. What is the [H₃O⁺] in a solution that consists of 1.2 M HClO and 2.3 M NaClO?

K_a = 3.5 × 10^–8

A. 7.8 × 10^–9 M

B. 1.8 × 10^–8 M

C. 6.7 × 10^–8 M

D. 1.6 × 10^–7 M

E. None of these choices are correct.

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

27. What is the [H₃O⁺] in a solution that consists of 0.15 M C₂N₂H₈ (ethylene diamine) and 0.35 C₂N₂H₉Cl? K_b = 4.7 × 10^–4

A. 2.0 × 10^–3 M

B. 1.1 × 10^–3 M

C. 6.3 × 10^–9 M

D. 2.1 × 10^–10 M

E. 5.0 × 10^–11 M

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

28. What is the [H₃O⁺] in a solution that consists of 1.5 M NH₃ and 2.5 NH₄Cl? K_b = 1.8 × 10^–5

A. 1.1 × 10^–5 M

B. 3.0 × 10^–6 M

C. 3.3 × 10^–9 M

D. 9.3 × 10^–10 M

E. None of these choices are correct.

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

29. What is the pK_a for the acid HA if a solution of 0.65 M HA and 0.85 M NaA has a pH of 4.75?

A. < 4.00

B. 4.63

C. 4.87

D. 5.02

E. > 5.50

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Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

30. A formic acid buffer containing 0.50 M HCOOH and 0.50 M HCOONa has a pH of 3.77. What will the pH be after 0.010 mol of NaOH has been added to 100.0 mL of the buffer?

A. 3.67

B. 3.78

C. 3.81

D. 3.85

E. 3.95

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Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

31. An acetic acid buffer containing 0.50 M CH₃COOH and 0.50 M CH₃COONa has a pH of 4.74. What will the pH be after 0.0020 mol of HCl has been added to 100.0 mL of the buffer?

A. 4.77

B. 4.71

C. 4.68

D. 4.62

E. None of these choices are correct.

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Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

32. A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH₃COOH. What is the pH of this buffer? K_a = 1.8 × 10^–5

A. 4.57

B. 4.52

C. 4.87

D. 4.92

E. 4.97

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

33. A buffer is prepared by adding 1.00 L of 1.0 M HCl to 750 mL of 1.5 M NaHCOO. What is the pH of this buffer? K_a = 1.7 × 10^–4

A. 2.87

B. 3.72

C. 3.82

D. 3.95

E. 4.66

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Bloom's: 3. Apply

Difficulty: Medium

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Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

34. If 10.0 g of NaF and 20.0 g of HF are dissolved in water to make one liter of solution, what will the pH be? For HF, K_a = 6.8 × 10^–4.

A. 7.13

B. 2.54

C. 1.57

D. 3.17

E. 4.86

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

35. A solution is prepared by dissolving 20.0 g of K₂HPO₄ and 25.0 g of KH₂PO₄ in enough water to produce 1.0 L of solution. What is the pH of this buffer? For phosphoric acid (H₃PO₄), K_a2 = 6.2 × 10^–8.

A. 7.70

B. 7.42

C. 7.21

D. 7.00

E. 6.72

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Difficulty: Medium

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Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

36. You need to use KH₂PO₄ and K₂HPO₄ to prepare a buffer with a pH of 7.45. Which of the following ratios of [base]/[acid] is required? For phosphoric acid, (H₃PO₄), K_a2 = 6.2 × 10^–8.

A. [base]/[acid] = 1.75

B. [base]/[acid] = 1.27

C. [base]/[acid] = 1.24

D. [base]/[acid] = 0.79

E. [base]/[acid] = 0.57

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Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

37. You need to prepare a buffer solution with a pH of 4.00, using NaF and HF. What ratio of the ratio of [base]/[acid] should be used in making the buffer? For HF, K_a = 7.2 × 10^–4.

A. [base]/[acid] = 0.14

B. [base]/[acid] = 0.42

C. [base]/[acid] = 2.36

D. [base]/[acid] = 7.20

E. None of these choices are correct.

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Difficulty: Easy

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Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

38. The pH of blood is 7.35. It is maintained in part by the buffer system composed of carbonic acid (H₂CO₃) and the bicarbonate (hydrogen carbonate, HCO₃^–) ion. What is the ratio of [bicarbonate]/[carbonic acid] at this pH? For carbonic acid, K_a1 = 4.2 × 10^–7.

A. [bicarbonate]/[carbonic acid] = 0.11

B. [bicarbonate]/[carbonic acid] = 0.38

C. [bicarbonate]/[carbonic acid] = 2.65

D. [bicarbonate]/[carbonic acid] = 9.4

E. None of these choices are correct.

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Difficulty: Easy

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Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

39. What mass of NaF must be added to 50.0 mL of a 0.500 M HF solution to achieve a pH of 3.25?

For HF, K_a = 7.2 × 10^–4.

A. 1.3 g

B. 0.69 g

C. 6.9 g

D. 23 g

E. 1.5 g

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Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

40. Two buffer solutions are prepared using acetic acid and sodium acetate. Solution A contains 20.0 g of acetic acid (CH₃COOH) and 5.0 g of sodium acetate CH₃COONa). Solution B contains 10.0 g of acetic acid and 25.0 g of sodium acetate. What is the difference between the pH values of these two solutions? For acetic acid, K_a = 1.8 × 10^–5.

A. 0.0

B. 1.0

C. 2.0

D. 2.3

E. 4.6

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Difficulty: Hard

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Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

41. A buffer is prepared by adding 150 mL of 1.0 M NaOH to 250 mL of 1.0 M NaH₂PO₄. How many moles of HCl must be added to this buffer solution to change the pH by 0.18 units? If necessary, assume the total volume remains unchanged at 400 mL.

A. 0.025 mol HCl

B. 0.063 mol HCl

C. 0.082 mol HCl

D. 0.50 mol HCl

E. 1.0 mol HCl

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Difficulty: Hard

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

42. At the equivalence point in an acid-base titration

A. the [H₃O⁺] equals the K_a of the acid.

B. the [H₃O⁺] equals the K_a of the indicator.

C. the amounts of acid and base which have been combined are in their stoichiometric ratio.

D. the pH is 7.0.

E. the pH has reached a maximum.

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Bloom's: 1. Remember

Difficulty: Easy

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Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

43. When a strong acid is titrated with a strong base, the pH at the equivalence point

A. is greater than 7.0.

B. is equal to 7.0.

C. is less than 7.0, but is not 3.5.

D. is equal to the pK_a of the acid.

E. is equal to 3.5.

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Difficulty: Easy

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Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

44. When a weak acid is titrated with a strong base, the pH at the equivalence point

A. is greater than 7.0.

B. is equal to 7.0.

C. is less than 7.0.

D. is equal to the pK_a of the acid.

E. is equal to 14.0 – pK_b, where pK_b is that of the base.

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Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

45. When a strong acid is titrated with a weak base, the pH at the equivalence point

A. is greater than 7.0.

B. is equal to 7.0.

C. is less than 7.0.

D. is equal to the pK_a of the acid.

E. is equal to the pK_b of the base.

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Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

46. When a weak acid is titrated with a weak base, the pH at the equivalence point

A. is greater than 7.0.

B. is equal to 7.0.

C. is less than 7.0.

D. is determined by the sizes of K_a and K_b.

E. is no longer affected by addition of base.

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Bloom's: 1. Remember

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

47. Which one of the following is the best representation of the titration curve that will be obtained in the titration of a weak acid (0.10 mol L^–1) with a strong base of the same concentration?

A. A

B. B

C. C

D. D

E. E

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

48. Which one of the following is the best representation of the titration curve that will be obtained in the titration of a weak base (0.10 mol L^–1) with HCl of the same concentration?

A. A

B. B

C. C

D. D

E. E

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

49. The indicator propyl red has K_a = 3.3 × 10^–6. What would be the approximate pH range over which it would change color?

A. 3.5–5.5

B. 4.5–6.5

C. 5.5–7.5

D. 6.5–8.5

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

50. Which of the following indicators would be the best to use when 0.050 M benzoic acid (K_a = 6.6 × 10^–5) is titrated with 0.05 M NaOH?

A. bromphenol blue, pH range: 3.0–4.5

B. bromcresol green, pH range: 3.8–5.4

C. alizarin, pH range: 5.7–7.2

D. phenol red, pH range: 6.9–8.2

E. phenolphthalein, pH range: 8.0–10.1

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

51. A 50.0-mL sample of 0.50 M HCl is titrated with 0.50 M NaOH. What is the pH of the solution after 28.0 mL of NaOH have been added to the acid?

A. 0.85

B. 0.75

C. 0.66

D. 0.49

E. 3.8

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

52. A 20.0-mL sample of 0.25 M HNO₃ is titrated with 0.15 M NaOH. What is the pH of the solution after 30.0 mL of NaOH have been added to the acid?

A. 2.00

B. 1.60

C. 1.05

D. 1.00

E. None of these choices are correct.

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

53. A 20.0-mL sample of 0.30 M HBr is titrated with 0.15 M NaOH. What is the pH of the solution after 40.3 mL of NaOH have been added to the acid?

A. 2.95

B. 3.13

C. 10.87

D. 11.05

E. 13.14

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

54. A 35.0-mL sample of 0.20 M LiOH is titrated with 0.25 M HCl. What is the pH of the solution after 23.0 mL of HCl have been added to the base?

A. 1.26

B. 1.67

C. 12.33

D. 12.74

E. 13.03

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

55. When 20.0 mL of 0.15 M hydrochloric acid is mixed with 20.0 mL of 0.10 M sodium hydroxide, the pH of the resulting solution is

A. 0.00.

B. 12.40.

C. 1.60.

D. 0.82.

E. 7.00.

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

56. A 25.0-mL sample of 0.35 M HCOOH is titrated with 0.20 M KOH. What is the pH of the solution after 25.0 mL of KOH has been added to the acid? K_a = 1.77 × 10^–4

A. 4.00

B. 3.88

C. 3.63

D. 3.51

E. 3.47

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Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

57. A 10.0-mL sample of 0.75 M CH₃CH₂COOH is titrated with 0.30 M NaOH. What is the pH of the solution after 22.0 mL of NaOH have been added to the acid? K_a = 1.3 × 10^–5

A. 5.75

B. 4.94

C. 4.83

D. 4.02

E. 3.95

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Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

58. A 25.0-mL sample of 0.10 M C₂H₃NH₂ (ethylamine) is titrated with 0.15 M HCl. What is the Ph of the solution after 9.00 mL of acid have been added to the amine? K_b = 6.5 × 10^–4

A. 11.08

B. 10.88

C. 10.74

D. 10.55

E. 10.49

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Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

59. A 25.0-mL sample of 1.00 M NH₃ is titrated with 0.15 M HCl. What is the pH of the solution after 15.00 mL of acid have been added to the ammonia solution? K_b = 1.8 × 10^–5

A. 10.26

B. 9.30

C. 9.21

D. 8.30

E. 8.21

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Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

60. A 20.0-mL sample of 0.30 M HClO was titrated with 0.30 M NaOH. The following data were collected during the titration.

mL NaOH added 5.00 10.00 1.00 2.00

pH 6.98 7.46 7.93 10.31

What is the Ka for HClO?

A. 1.1 × 10^–7

B. 3.5 × 10^–8

C. 1.2 × 10^–8

D. 4.9 × 10^–11

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

61. Which one of the following is the best representation of the titration curve that will be obtained in the titration of a weak diprotic acid H₂A (0.10 mol L^–1) with a strong base of the same concentration?

A. A

B. B

C. C

D. D

E. E

Bloom's: 2. Understand

Difficulty: Hard

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

62. A diprotic acid H₂A has K_a1 = 1 × 10^–4 and K_a2 = 1 × 10^–8. The corresponding base A^2– is titrated with aqueous HCl, both solutions being 0.1 mol L^–1. Which one of the following diagrams best represents the titration curve which will be seen?

A. A

B. B

C. C

D. D

E. E

Bloom's: 2. Understand

Difficulty: Hard

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

63. A 20.0-mL sample of 0.50 M H₂C₆H₆O₆ (ascorbic acid, a diprotic acid) was titrated with 0.50 M NaOH. The following data were gathered during the titration.

mL NaOH added 10.00 20.00 30.00 40.00

pH 4.17 5.21 11.55 12.89

What is K_a2 for ascorbic acid?

A. 6.8 × 10^–5

B. 6.2 × 10^–6

C. 6.2 × 10^–7

D. 6.2 × 10^–8

E. 2.8 × 10^–12

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

64. What volume of 0.200 M KOH must be added to 17.5 mL of 0.135 M H₃PO₄ to reach the third equivalence point?

A. 3.94 mL

B. 11.8 mL

C. 17.5 mL

D. 23.6 mL

E. 35.4 mL

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Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

65. A sample of a monoprotic acid (HA) weighing 0.384 g is dissolved in water and the solution is titrated with aqueous NaOH. If 30.0 mL of 0.100 M NaOH is required to reach the equivalence point, what is the molar mass of HA?

A. 37.0 g/mol

B. 81.0 g/mol

C. 128 g/mol

D. 20.3 g/mol

E. 211 g/mol

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

66. When 0.300 g of a diprotic acid was titrated with 0.100 M LiOH, 40.0 mL of the LiOH solution was needed to reach the second equivalence point. Identify the formula of the diprotic acid.

A. H₂S

B. H₂C₂O₄

C. H₂C₄H₄O₆

D. H₂Se

E. H₂Te

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

67. What volume of 0.500 M H₂SO₄ is needed to react completely with 20.0 mL of 0.400 M LiOH?

A. 4.00 mL

B. 8.00 mL

C. 12.5 mL

D. 16.0 mL

E. 32.0 mL

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Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

68. A change in pH will significantly affect the solubility of which, if any, of the following compounds?

A. BaF₂

B. CuCl

C. CuBr

D. AgI

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility and pH

Topic: Solubility

69. The solubility of aluminum hydroxide in water ______________ when dilute nitric acid is added to it.

A. increases

B. decreases

C. does not change

D. first increases, then decreases

E. first decreases, then increases

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility and pH

Topic: Solubility

70. A saturated solution of calcium hydroxide, Ca(OH)₂, is in contact with excess solid Ca(OH)₂. Which of the following statements correctly describes what will happen when aqueous HCl (a strong acid) is added to this mixture, and system returns to equilibrium? (For Ca(OH)₂, K_sp = 6.5 × 10^–6)

A. The solubility of Ca(OH)₂ will be unchanged.

B. The OH^– concentration will decrease and the Ca²⁺ concentration will increase.

C. The OH^– concentration will increase and the Ca²⁺ concentration will decrease.

D. The concentrations of both Ca²⁺ and OH^– will increase.

E. The solubility of Ca(OH)₂ will decrease.

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility and pH

Topic: Solubility

71. The solubility of silver chloride _______________ when dilute nitric acid is added to it.

A. increases

B. decreases

C. does not change

D. first increases, then decreases

E. first decreases, then increases

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Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility and pH

Topic: Solubility

72. Write the ion product expression for magnesium fluoride, MgF₂.

A.

B.

C.

D.

E.

Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

73. Write the ion product expression for silver sulfide, Ag₂S.

A.

B.

C.

D.

E.

Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

74. Write the ion product expression for calcium phosphate, Ca₃(PO₄)₂.

A.

B.

C.

D.

E. None of these choices are correct.

Bloom's: 3. Apply

Difficulty: Easy

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

75. The solubility of lead(II) chloride is 0.45 g/100 mL of solution. What is the K_sp of PbCl₂?

A. 4.9 × 10^–2

B. 1.7 × 10^–5

C. 8.5 × 10^–6

D. 4.2 × 10^–6

E. < 1.0 × 10^–6

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

76. The solubility of calcium chromate is 1.56 × 10^–3 g/100 mL of solution. What is the K_sp for CaCrO₄?

A. 2.4 × 10^–4

B. 1.5 × 10^–5

C. 7.6 × 10^–6

D. 1.0 × 10^–8

E. < 1.0 × 10^–8

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

77. The solubility of silver chromate is 0.0287 g/1.0 L of solution. What is the K_sp for Ag₂CrO₄?

A. 9.5 × 10^–5

B. 2.4 × 10^–5

C. 2.6 × 10^–12

D. 6.5 × 10^–13

E. < 1.0 × 10^–13

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

78. The solubility of magnesium phosphate is 2.27 × 10^–3 g/1.0 L of solution. What is the K_sp for Mg₃(PO₄)₂?

A. 6.5 × 10^–12

B. 6.0 × 10^–14

C. 5.2 × 10^–24

D. 4.8 × 10^–26

E. 1.0 × 10^–26

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

79. Calculate the solubility of barium carbonate, BaCO₃, in pure water. K_sp = 2.0 × 10^–9

A. 1.3 × 10^–3 M

B. 3.2 × 10^–5 M

C. 2.2 × 10^–5 M

D. 4.5 × 10^–5 M

E. 4.0 × 10^–18 M

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

80. Calculate the solubility of silver oxalate, Ag₂C₂O₄, in pure water. K_sp = 1.0 × 10^–11

A. 1.4 × 10^–4 M

B. 8.2 × 10^–5 M

C. 5.4 × 10^–5 M

D. 3.2 × 10^–6 M

E. 2.5 × 10^–12 M

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

81. Calculate the solubility of strontium fluoride, SrF₂, in pure water. K_sp = 2.6 × 10^–9

A. 1.4 × 10^–3 M

B. 3.4 × 10^–4 M

C. 8.7 × 10^–4 M

D. 5.1 × 10^–5 M

E. < 1.0 × 10^–5 M

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

82. Calculate the solubility of silver phosphate, Ag3PO4, in pure water. K_sp = 2.6 × 10^–18

A. 4.0 × 10^–5 M

B. 1.8 × 10^–5 M

C. 4.0 × 10^–6 M

D. 1.5 × 10^–5 M

E. < 1.0 × 10^–5 M

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Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

83. Which of the following substances has the greatest solubility in water?

A. MgCO₃, K_sp = 3.5 × 10^–8

B. NiCO₃, K_sp = 1.3 × 10^–7

C. AgIO₃, K_sp = 3.1 × 10^–8

D. CuBr, K_sp = 5.0 × 10^–9

E. AgCN, K_sp = 2.2 × 10^–16

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

84. Which of the following substances has the greatest solubility in water?

A. PbI₂, K_sp = 7.9 × 10^–9

B. BaF₂, K_sp = 1.5 × 10^–6

C. Ca(OH)₂, K_sp = 6.5 × 10^–6

D. Zn(IO₃)₂, K_sp = 3.9 × 10^–6

E. Ag₂SO₄, K_sp = 1.5 × 10^–5

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

85. Which of the following substances has the greatest solubility in water?

A. Ba(IO₃)₂, K_sp = 1.5 × 10^–9

B. PbF₂, K_sp = 3.6 × 10^–8

C. SrSO₄, K_sp = 3.2 × 10^–7

D. CuCl, K_sp = 1.9 × 10^–7

E. CdS, K_sp = 1.0 × 10^–24

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Bloom's: 2. Understand

Difficulty: Hard

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

86. Barium sulfate (BaSO₄) is a slightly soluble salt, with K_sp = 1.1 × 10^–10. What mass of Ba²⁺ ions will be present in 1.0 L of a saturated solution of barium sulfate?

A. < 10^–7 g

B. 1.0 × 10^–5 g

C. 0.0014 g

D. 0.0024 g

E. > 0.05 g

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

87. Use the following information to calculate the solubility product constant, K_sp, for PbCl₂. A saturated solution of PbCl₂ in water was prepared and filtered. From the filtrate, 1.0 L was measured out into a beaker and evaporated to dryness. The solid PbCl₂ residue recovered in the beaker amounted to 0.0162 moles.

A. K_sp = 6.9 × 10^–8

B. K_sp = 4.3 × 10^–6

C. K_sp = 1.7 × 10^–5

D. K_sp = 2.6 × 10^–4

E. K_sp = 3.2 × 10^–2

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Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

88. Use the following information to calculate the solubility product constant, K_sp, for CuCl. A saturated solution of CuCl in water was prepared and filtered. From the filtrate, 1.0 L was measured out into a beaker and evaporated to dryness. The solid CuCl residue recovered in the beaker was found to weigh 0.041g.

A. K_sp = 1.7 × 10^y9

B. K_sp = 1.7 × 10^y7

C. K_sp = 1.7 × 10^–5

D. K_sp = 4.3 × 10^–4

E. K_sp = 2.1 × 10^–2

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Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

89. Assuming that the total volume does not change after 0.200 g of KCl is added to 1.0 L of a saturated aqueous solution of AgCl, calculate the number of moles of Ag⁺ ion in the solution after equilibrium has been reestablished. For AgCl, K_sp = 1.8 × 10^–10.

A. 1.8 × 10^–10 mol Ag⁺

B. 9.0 × 10^–10 mol Ag⁺

C. 9.0 × 10^–9 mol Ag⁺

D. 6.7 × 10^–8 mol Ag⁺

E. 1.3 × 10^–5 mol Ag⁺

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility and Common Ion Effect

Topic: Solubility

90. What is the maximum mass of KCl that can be added to1.0 L of a 0.010 M lead(II) chloride solution without causing any precipitation of lead(II) chloride? Assume that addition of KCl does not affect the solution volume. For lead(II) chloride, K_sp = 1.6 × 10^–5.

A. 3.0 g

B. 1.5 g

C. 0.8 g

D. 1.0 g

E. 0.2 g

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility and Common Ion Effect

Topic: Solubility

91. Calculate the solubility of magnesium sulfate, MgSO₄, when placed into a 0.10 M MgCl₂ solution. K_sp = 5.9 × 10^–3

A. 4.2 × 10^–2 M

B. 5.9 × 10^–2 M

C. 7.7 × 10^–2 M

D. 3.5 × 10^–5 M

E. 3.5 × 10^–6 M

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility and Common Ion Effect

Topic: Solubility

92. Calculate the solubility of silver chromate, Ag₂CrO₄, in 0.005 M Na₂CrO₄. K_sp = 2.6 × 10^–12

A. 1.4 × 10^–4 M

B. 3.4 × 10^–5 M

C. 1.1 × 10^–5 M

D. 1.6 × 10^–6 M

E. < 1.0 × 10^–6 M

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility and Common Ion Effect

Topic: Solubility

93. Calculate the solubility of lead(II) iodide, PbI₂, in 0.025 M KI. K_sp = 7.9 × 10^–9

A. 4.5 × 10^–2 M

B. 2.8 × 10^–2 M

C. 8.9 × 10^–5 M

D. 5.0 × 10^–5 M

E. 1.3 × 10^–5 M

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility and Common Ion Effect

Topic: Solubility

94. A lab technician adds 0.015 mol of KOH to 1.00 L of 0.0010 M Ca(NO₃)₂. K_sp = 6.5 × 10^–6 for Ca(OH)₂). Which of the following statements is correct?

A. Calcium hydroxide precipitates until the solution is saturated.

B. The solution is unsaturated and no precipitate forms.

C. The concentration of calcium ions is reduced by the addition of the hydroxide ions.

D. One must know K_sp for calcium nitrate to make meaningful predictions on this system.

E. The presence of KOH will raise the solubility of Ca(NO₃)₂.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Predicting Precipitation Reactions (Q vs. Ksp)

Topic: Solubility

95. A lab technician adds 0.20 mol of NaF to 1.00 L of 0.35 M cadmium nitrate, Cd(NO₃)₂. Which of the following statements is correct? K_sp = 6.44 × 10^–3 for CdF₂.

A. Cadmium fluoride precipitates until the solution is saturated.

B. The solution is unsaturated and no precipitate forms.

C. The solubility of cadmium fluoride is increased by the presence of additional fluoride ions.

D. One must know K_sp for cadmium nitrate to make meaningful predictions on this system.

E. The presence of NaF will raise the solubility of Cd(NO₃)₂.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Predicting Precipitation Reactions (Q vs. Ksp)

Topic: Solubility

96. What is the maximum amount of sodium sulfate that can be added to 1.00 L of 0.0020 M Ca(NO₃)₂ before precipitation of calcium sulfate begins? K_sp = 2.4 × 10^–5 for calcium sulfate.

A. 1.2 × 10^–2 mol

B. 4.9 × 10^–3 mol

C. 3.5 × 10^–3 mol

D. 1.2 × 10^–5 mol

E. 4.8 × 10^–8 mol

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Predicting Precipitation Reactions (Q vs. Ksp)

Topic: Solubility

97. Consider the dissolution of MnS in water (K_sp = 3.0 × 10^–14).

MnS(s) + H₂O(l) Mn²⁺(aq) + HS^–(aq) + OH^–(aq)

How is the solubility of manganese(II) sulfide affected by the addition of aqueous potassium hydroxide to the system?

A. The solubility will be unchanged.

B. The solubility will decrease.

C. The solubility will increase.

D. The amount of KOH added must be known before its effect can be predicted.

E. The pK_a of H₂S is needed before a reliable prediction can be made.

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility and pH

Topic: Solubility

98. The lab technician Anna Lytic adds 2.20 mol KOH to 1.00 L of 0.5 M Al(NO₃)₃. What is the concentration of aluminum ions after the aluminum nitrate has reacted with the potassium hydroxide? K_f = 3.0 × 10³³ for Al(OH)₄^–

A. 1.8 × 10^–7 M

B. 9.1 × 10^–18 M

C. 1.0 × 10^–31 M

D. 3.3 × 10^–34 M

E. 7.1 × 10^–36 M

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Predicting Precipitation Reactions (Q vs. Ksp)

Topic: Solubility

99. A solution is prepared by adding 4.50 mol of sodium hydroxide to 1.00 L of 1.00 M Co(NO₃)₂. What is the equilibrium concentration of cobalt ions? K_f = 5.0 × 10⁹ for Co(OH)₄^2–

A. 1.1 × 10^–2 M

B. 1.4 × 10^–5 M

C. 3.2 × 10^–9 M

D. 2.0 × 10^–10 M

E. 4.9 × 10^–13 M

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Predicting Precipitation Reactions (Q vs. Ksp)

Topic: Solubility

100. The concentration of the complex ion in each of following solutions is 1.00 M. In which of the solutions will the concentration of the uncomplexed metal ion be the greatest?

Hg(CN)₄^2– K_f = 9.3 × 10³⁸

Be(OH) ₄^2– K_f = 4.0 × 10¹⁸

Zn(OH) ₄^2– K_f = 3.0 × 10¹⁵

Cu(NH₃)₄²⁺ K_f = 5.6 × 10¹¹

CdI₄^2– K_f = 1.0 × 10⁶

A. Hg²⁺

B. Be²⁺

C. Zn²⁺

D. Cu²⁺

E. Cd²⁺

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Complex Ion Equilibrium

Topic: Solubility

101. Calculate the solubility of zinc hydroxide, Zn(OH)₂, in 1.00 M NaOH.

K_sp = 3.0 × 10^–16 for Zn(OH)₂, K_f = 3.0 × 10¹⁵ for Zn(OH)₄^2–

A. 0.60 M

B. 0.52 M

C. 0.37 M

D. 0.32 M

E. 0.24 M

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Hard

Gradable: automatic

Subtopic: Complex Ion Equilibrium

Topic: Solubility

102. A solution is prepared by mixing 50.0 mL of 0.50 M Cu(NO₃)₂ with 50.0 mL of 0.50 M Co(NO₃)₂. Sodium hydroxide is added to the mixture. Which hydroxide precipitates first and what concentration of hydroxide ions present in solution will accomplish the separation?

K_sp = 2.2 × 10^–20 for Cu(OH)₂, K_sp = 1.3 × 10^–15 for Co(OH)₂

A. Co(OH)₂; [OH^–] = 6.9 × 10^–6 M

B. Co(OH) ₂; [OH^–] = 2.6 × 10^–7 M

C. Cu(OH) ₂; [OH^–] = 1.8 × 10^–7 M

D. Cu(OH) ₂; [OH^–] = 1.1 × 10^–9 M

E. Cu(OH) ₂; [OH^–] = 1.0 × 10^–17 M

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Fractional Precipitation

Topic: Solubility

103. The salts X(NO₃)₂ and Y(NO₃)₂ (where X⁺ and Y⁺ are metal ions) are dissolved in water to give a solution which is 0.1 M in each of them. Using the K_sp values listed below, decide which aqueous reagent, if any, will definitely precipitate X⁺ before precipitating Y+ from solution.

Given K_sp values:

XCl₂, 1 × 10^–5 YCl₂, 1 × 10^–10 X(OH)₂, 1 × 10^–10 Y(OH)₂, 1 × 10^–5

A. 1 M NaCl

B. 1 M HCl

C. 1 M HNO₃

D. 1 M NaOH

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Fractional Precipitation

Topic: Solubility

104. The salts X(NO₃)₂ and Y(NO₃)₂ (where X⁺ and Y⁺ are metal ions) are dissolved in water to give a solution which is 0.1 M in each of them. Using the K^sp values listed below, decide which aqueous reagent, if any, will definitely precipitate X⁺ before precipitating Y⁺ from solution.

Given Ksp values:

XCl₂, 1 × 10^–5 YCl₂, 1 × 10^–10 X(OH)₂, 1 × 10^–10 Y(OH)₂, 1 × 10^–5

A. 1 M NH₃

B. 1 M HCl

C. 1 M HNO₃

D. 1 M NaCl

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Fractional Precipitation

Topic: Solubility

105. The salts X(NO₃)₂ and Y(NO₃)₂ (where X⁺ and Y⁺ are metal ions) are dissolved in water to give a solution which is 0.1 M in each of them. Using the K_sp values listed below, decide which aqueous reagent, if any, will definitely precipitate X⁺ before precipitating Y⁺ from solution.

Given K_sp values:

XCl₂, 1 × 10^–5 YCl₂, 1 × 10^–10 X(OH)₂, 1 × 10^–10 Y(OH)₂, 1 × 10^–5

A. 1 M NaNO₃

B. 1 M HCl

C. 1 M HNO₃

D. 1 M NaCl

E. None of these choices are correct.

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Fractional Precipitation

Topic: Solubility

106. The salts X(NO₃)₂ and Y(NO₃)₂ (where X⁺ and Y⁺ are metal ions) are dissolved in water to give a solution which is 0.1 M in each of them. Which of the answers gives the concentration of chloride ions will precipitate the most YCl₂ without precipitating any XCl₂?

Given K_sp values: XCl₂, 2 × 10^–5 YCl₂, 1 × 10^–10

A. 1 M Cl^–

B. 0.1 M Cl^–

C. 0.01 M Cl^–

D. 0.001 M Cl^–

E. 0.0001 M Cl^–

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Fractional Precipitation

Topic: Solubility

107. A CH₃COOH/CH₃COO– buffer can be produced by adding a strong acid to a solution of CH₃COO– ions.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

108. Increasing the concentrations of the components of a buffer solution will increase the buffer range.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

109. Increasing the concentrations of the components of a buffer solution will increase the buffer capacity.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Easy

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

110. If the pH of a buffer solution is greater than the pK_a value of the buffer acid, the buffer will have more capacity to neutralize added base than added acid.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Medium

Gradable: automatic

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation)

Topic: Acids and Bases

111. The end point in a titration is defined as the point when the indicator changes color.

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

112. The equivalence point in a titration is defined as the point when the indicator changes color.

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Easy

Gradable: automatic

Subtopic: Acid-Base Titrations and Indicators

Topic: Acids and Bases

113. For a diprotic acid H₂A, the relationship K_a1 > K_a2 is always true.

Accessibility: Keyboard Navigation

Bloom's: 1. Remember

Difficulty: Medium

Gradable: automatic

Subtopic: Polyprotic Acids

Topic: Acids and Bases

114. The solubility of salt MX (solubility product constant K_sp) in water will always be greater than that of salt MX₃ (solubility product constant K'_sp) provided that K_sp > K'_sp.

Accessibility: Keyboard Navigation

Bloom's: 2. Understand

Difficulty: Hard

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

115.Calculate the molar solubility of silver carbonate in 1.0 M sodium carbonate solution. (K_sp for Ag₂CO₃ = 8.1 x 10^-12)

A. 8.1 x 10^-12 M

B. 2.8 x 10^-6 M

C. 1.4 x 10^-6 M

D. 1.4 x 10^-8 M

E. 2.0 x 10^-4 M

Accessibility: Keyboard Navigation

Bloom's: 3. Apply

Difficulty: Medium

Gradable: automatic

Subtopic: Solubility Product (Ksp)

Topic: Solubility

Category # of Questions

Accessibility: Keyboard Navigation 107

Bloom's: 1. Remember 8

Bloom's: 2. Understand 43

Bloom's: 3. Apply 64

Difficulty: Easy 28

Difficulty: Hard 18

Difficulty: Medium 69

Gradable: automatic 115

Subtopic: Acid-Base Titrations and Indicators 28

Subtopic: Buffer Solutions (Common Ion Effect and the Henderson-Hasselbalch Equation) 45

Subtopic: Complex Ion Equilibrium 2

Subtopic: Fractional Precipitation 5

Subtopic: Polyprotic Acids 1

Subtopic: Predicting Precipitation Reactions (Q vs. Ksp) 5

Subtopic: Solubility and Common Ion Effect 5

Subtopic: Solubility and pH 5

Subtopic: Solubility Product (Ksp) 19

Topic: Acids and Bases 74

Topic: Solubility 41