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), Ka2 = 6.2 × 10-8.

A) 7.70 B) 7.42 C) 7.21 D) 7.00 E) 6.72 A) 7.70 B) 7.42 C) 7.21 D) 7.00 E) 6.72

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, Ka = 6.8 × 10-5

A) 3.76 B) 3.99 C) 4.34 D) 4.57 E) 5.66 A) 3.76 B) 3.99 C) 4.34 D) 4.57 E) 5.66

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, Ka1 = 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. 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.

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 A) 3.94 mL B) 11.8 mL C) 17.5 mL D) 23.6 mL E) 35.4 mL

Calculate the solubility of zinc hydroxide, Zn(OH)2, in 1.00 M NaOH. Ksp = 3.0 × 10-16 for Zn(OH)2, Kf = 3.0 × 1015 for Zn(OH)42-

A) 0.60 M B) 0.52 M C) 0.37 M D) 0.32 M E) 0.24 M A) 0.60 M B) 0.52 M C) 0.37 M D) 0.32 M E) 0.24 M

Exam 19: Ionic Equilibria in Aqueous Systems

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.

(True/False)

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Question 41

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?

(Multiple Choice)

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Question 42

Write the ion product expression for silver sulfide, Ag₂S.

(Multiple Choice)

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Question 43

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

(Multiple Choice)

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Question 44

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

(Multiple Choice)

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Question 45

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?

(Multiple Choice)

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Question 46

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?

(Multiple Choice)

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Question 47

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.

(Multiple Choice)

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Question 48

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

(Multiple Choice)

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Question 49

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

(Multiple Choice)

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Question 50

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.

(Multiple Choice)

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Question 51

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

(Multiple Choice)

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Question 52

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

(Multiple Choice)

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Question 53

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?

(Multiple Choice)

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Question 54

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.

(Multiple Choice)

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Question 55

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

(Multiple Choice)

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Question 56

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-

(Multiple Choice)

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Question 57

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)

(Multiple Choice)

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Question 58

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

(Multiple Choice)

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Question 59

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?

(Multiple Choice)

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Question 60

Showing 41 - 60 of 114

Exam 19: Ionic Equilibria in Aqueous Systems

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

A diprotic acid H2A has Ka1 = 1 × 10-4 and Ka2 = 1 × 10-8. The corresponding base A2- 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?

Write the ion product expression for silver sulfide, Ag2S.

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

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

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?

Consider the dissolution of MnS in water (Ksp = 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 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), Ka2 = 6.2 × 10-8.

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

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, Ka = 6.8 × 10-5

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, Ka1 = 4.2 × 10-7.

The solubility of calcium chromate is 1.56 × 10-3 g/100 mL of solution. What is the Ksp for CaCrO4?

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

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?

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, Ka = 7.2 × 10-4.

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? Kb = 6.5 × 10-4

Calculate the solubility of zinc hydroxide, Zn(OH)2, in 1.00 M NaOH. Ksp = 3.0 × 10-16 for Zn(OH)2, Kf = 3.0 × 1015 for Zn(OH)42-

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, Ksp = 6.5 × 10-6)

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? Ka = 1.77 × 10-4

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?

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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.

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?

Write the ion product expression for silver sulfide, Ag₂S.

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?

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 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.

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

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.

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

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?

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 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

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 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 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

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?