Question 1

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

Accepted Answer

A)  HOC 6H 4OCOOH, K a = 1.0 × 10 −3
B)  C 6H 4(COOH) 2, K a = 2.9 × 10 −4
C)  CH 3COOH, K a = 1.8 × 10 −5
D)  C 5H 5O 5COOH, K a = 4.0 × 10 −6
E)  HBrO, K a = 2.3 × 10 −9F) C) and D)
G) A) and B)

Question 2

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, Ka = 7.2 × 10−4.

Accepted Answer

A)  1.3 g
B)  0.69 g
C)  6.9 g
D)  23 g
E)  1.5 gF) B) and C)
G) B) and E)

Question 3

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

Accepted Answer

A)  BaF 2
B)  CuCl
C)  CuBr
D)  AgI
E)  None of these choices are correct.F) A) and C)
G) B) and D)

Question 4

Calculate the solubility of magnesium sulfate, MgSO4, when placed into a 0.10 M MgCl2 solution. Ksp = 5.9 × 10−3

Accepted Answer

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  MF) C) and D)
G) A) and B)

Question 5

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? −1)  with a strong base of the same concentration?   A) A B) B C) C D) D E) E" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  A
B)  B
C)  C
D)  D
E)  EF) C) and D)
G) A) and B)

Question 6

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

Accepted Answer

A)  6.51
B)  6.91
C)  7.51
D)  7.90
E)  8.13F) B) and D)
G) A) and D)

Question 7

Calculate the solubility of silver phosphate, Ag3PO4, in pure water. Ksp = 2.6 × 10−18

Accepted Answer

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)  −5  MF) A) and E)
G) C) and D)

Question 8

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

Accepted Answer

A)  2.
B)  3.
C)  4.
D)  5.
E)  6.F) C) and E)
G) D) and E)

Question 9

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, Ksp = 1.8 × 10−10.

Accepted Answer

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 +F) A) and E)
G) A) and D)

Question 10

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

Accepted Answer

A) True 
 B)False

Question 11

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. a 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." class="answers-bank-image d-inline" rel="preload" > What is the Ka for HClO?

Accepted Answer

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.F) A) and B)
G) A) and C)

Question 12

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

Accepted Answer

A)  [H 2PO 4 −] = 0.50 M, [HPO 4 2−] = 0.50 M
B)  [H 2PO 4 −] = 1.0 M, [HPO 4 2−] = 1.0 M
C)  [H2PO4−] = 1.0 M, [HPO42−] = 0.50 M
D)  [H2PO4−] = 0.50 M, [HPO42−] = 1.0 M
E)  [H 2PO 4 −] = 0.75 M, [HPO 4 2−] = 1.0 MF) A) and B)
G) All of the above

Question 13

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

Accepted Answer

A)   3(PO4) 2. 
A)     
B)     
C)     
D)     
E)  None of these choices are correct." class="answers-bank-image d-inline" rel="preload" >
B)   3(PO4) 2. 
A)     
B)     
C)     
D)     
E)  None of these choices are correct." class="answers-bank-image d-inline" rel="preload" >
C)   3(PO4) 2. 
A)     
B)     
C)     
D)     
E)  None of these choices are correct." class="answers-bank-image d-inline" rel="preload" >
D)   3(PO4) 2. 
A)     
B)     
C)     
D)     
E)  None of these choices are correct." class="answers-bank-image d-inline" rel="preload" >
E)  None of these choices are correct.F) None of the above
G) A) and E)

Question 14

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

Accepted Answer

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 NH 3
C)  0.10 mol L −1 HCl and 0.05 mol L −1 NH 3
D)  0.10 mol L −1 HCl and 0.20 mol L −1 CH 3COOH
E)  0.10 mol L −1 HCl and 0.20 mol L −1 NaClF) C) and E)
G) A) and E)

Question 15

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

Accepted Answer

A)  CH 3COOH, NaH 2PO 4
B)  H 2CO 3, HCO 3 −
C)  H 2PO 4 − , HCO 3 −
D)  HSO 4 − , HSO 3 −
E)  None of these choices are correct.F) B) and D)
G) C) and D)

Question 16

Calculate the solubility of silver chromate, Ag2CrO4, in 0.005 M Na2CrO4. Ksp = 2.6 × 10−12

Accepted Answer

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)  −6  MF) All of the above
G) B) and E)

Question 17

Calculate the solubility of silver oxalate, Ag2C2O4, in pure water. Ksp = 1.0 × 10−11

Accepted Answer

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  MF) None of the above
G) D) and E)

Question 18

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

Accepted Answer

A)  increases
B)  decreases
C)  does not change
D)  first increases, then decreases
E)  first decreases, then increasesF) A) and D)
G) C) and E)

Question 19

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

Accepted Answer

A)  0.00.
B)  12.40.
C)  1.60.
D)  0.82.
E)  7.00.F) A) and C)
G) B) and D)

Question 20

At the equivalence point in an acid-base titration

Accepted Answer

A)  the [H 3O +] equals the K a of the acid.
B)  the [H 3O +] 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.F) D) and E)
G) All of the above

Exam 19: Ionic Equilibria in Aqueous Systems

Calculate the solubility of silver oxalate, Ag2C2O4, in pure water. Ksp = 1.0 × 10−11

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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. What is the Ka for HClO?

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Calculate the solubility of silver phosphate, Ag3PO4, in pure water. Ksp = 2.6 × 10−18

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

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

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At the equivalence point in an acid-base titration

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

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

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

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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, Ksp = 1.8 × 10−10.

Correct AnswerverifiedShow Answer

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

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

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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, Ka = 7.2 × 10−4.

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

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Calculate the solubility of magnesium sulfate, MgSO4, when placed into a 0.10 M MgCl2 solution. Ksp = 5.9 × 10−3

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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

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Calculate the solubility of silver chromate, Ag2CrO4, in 0.005 M Na2CrO4. Ksp = 2.6 × 10−12

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

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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?

Correct AnswerverifiedShow Answer

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

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

Correct Answer
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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. What is the K_a for HClO?

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

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

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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.

Correct Answer
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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.

Correct Answer
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Correct Answer
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Calculate the solubility of magnesium sulfate, MgSO₄, when placed into a 0.10 M MgCl₂solution. K_sp = 5.9 × 10⁻³

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What is the pH of a buffer that consists of 0.20 M NaH₂PO₄and 0.40 M Na₂HPO₄? For NaH₂PO₄, K_a = 6.2 × 10⁻⁸

Correct Answer
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Calculate the solubility of silver chromate, Ag₂CrO₄, in 0.005 M Na₂CrO₄. K_sp = 2.6 × 10⁻¹²

Correct Answer
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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?

Correct Answer
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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

Correct Answer
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