Question 1

Write an equation showing the net reaction that occurs when a strong acid is added to a CO32-/HCO3-  buffer solution (for carbonic acid, Ka1 = 4.2 * 10-7, Ka2 = 2.4 * 10-8):

Accepted Answer

CO₃^2- +...

Question 2

Assuming equal concentrations of conjugate base and acid, which one of the following mixtures is suitable for making a buffer solution with an optimum pH of 4.6-4.8?

Accepted Answer

A)  CH3COO2Na / CH3COOH (Ka = 1.8 * 10-5) 
B)  NH3 / NH4Cl (Ka = 5.6 * 10-10) 
C)  NaOCl / HOCl (Ka = 3.2 * 10-8) 
D)  NaNO2 / HNO2 (Ka = 4.5 * 10-4) 
E)  NaCl / HClF) D) and E)
G) A) and E)

Question 3

What mass of ammonium nitrate must be added to 350. mL of a 0.150 M solution of ammonia to give a buffer having a pH of 9.00? (Kb(NH3) = 1.8 * 10-5)

Accepted Answer

A)  7.6 g
B)  2.4 g
C)  5.4 g
D)  11 g
E)  3.3 gF) B) and C)
G) C) and D)

Question 4

You are asked to go into the lab and prepare an acetic acid - sodium acetate buffer solution with a pH of 4.00 ± 0.02. What molar ratio of CH3COOH to CH3COONa should be used?

Accepted Answer

A)  0.18
B)  0.84
C)  1.19
D)  5.50
E)  0.10F) A) and C)
G) C) and D)

Question 5

The molar solubility of tin(II) iodide is 1.28 * 10-2 mol/L. What is Ksp for this compound?

Accepted Answer

A)  8.4 * 10-6
B)  1.28 * 10-2
C)  4.2 * 10-6
D)  1.6 * 10-4
E)  2.1 * 10-6F) A) and B)
G) C) and E)

Question 6

NaCl is added slowly to a solution that is 0.010 M each in Cu+, Ag+, and Au+. The Ksp's for CuCl, AgCl, and AuCl are 1.9 * 10-7, 1.8 * 10-10, and 2.0 * 10-13, respectively. Which compound will precipitate first?

Accepted Answer

The answer of NaCl is added slowly to a solution...

Question 7

The solubility of a salt increases as its Ksp increases.

Accepted Answer

A) True 
 B)False

Question 8

What is the pH at the equivalence point in the titration of 100 mL of 0.10 M HCl with 0.10 M NaOH?

Accepted Answer

A)  1.0
B)  6.0
C)  7.0
D)  8.0
E)  13.0F) A) and B)
G) D) and E)

Question 9

A 50.0 mL sample of 2.0 * 10-4 M CuNO3 is added to 50.0 mL of 4.0 M NaCN. The formation constant of the complex ion Cu(CN)32- is 1.0 * 109. What is the copper(I)ion concentration in this system at equilibrium?

Accepted Answer

1.3 * 10<s...

Question 10

Calculate the silver ion concentration in a saturated solution of silver(I) carbonate (Ksp = 8.1 * 10-12) .

Accepted Answer

A)  5.0 * 10-5 M
B)  2.5 * 10-4 M
C)  1.3 * 10-4 M
D)  2.0 * 10-4 M
E)  8.1 * 10-4 MF) A) and B)
G) B) and E)

Question 11

Will a precipitate of magnesium fluoride form when 200. mL of 1.9 * 10-3 M MgCl2 are added to 300. mL of 1.4 * 10-2 M NaF? [Ksp (MgF2) = 6.9 * 10-9]

Accepted Answer

A)  Yes, Q > Ksp
B)  No, Q sp
C)  No, Q = Ksp
D)  Yes, Q spE) None of the above
F) B) and C)

Question 12

A saturated sodium carbonate solution at 100°C contains 45.5 g of dissolved sodium carbonate per 100. mL of solution. The solubility product constant for sodium carbonate at this temperature is

Accepted Answer

A)  79.0.
B)  0.316.
C)  0.0790.
D)  36.8.
E)  316.F) A) and C)
G) A) and B)

Question 13

An environmental chemist obtained a 200. mL sample of lake water believed to be contaminated with a single monoprotic strong acid. Titrating this sample with a 0.0050 M NaOH(aq)required 7.3 mL of the NaOH solution to reach the endpoint. What is the pH of the lake?

Accepted Answer

The answer of An environmental chemist obtained a 200. mL...

Question 14

The solubility product for calcium phosphate is Ksp = 1.3 * 10-26. What is the molar solubility of calcium phosphate?

Accepted Answer

A)  1.3 * 10-26 M
B)  1.5 * 10-7 M
C)  2.6 * 10-6 M
D)  4.6 * 10-6 M
E)  6.6 * 10-6 MF) A) and D)
G) All of the above

Question 15

Which of the following would decrease the Ksp for PbI2?

Accepted Answer

A)  Lowering the pH of the solution
B)  Adding a solution of Pb(NO3) 2
C)  Adding a solution of KI
D)  None of the above-the Ksp of a compound is constant at constant temperature.E) A) and D)
F) A) and C)

Question 16

A solution is prepared by mixing 500. mL of 0.10 M NaOCl and 500. mL of 0.20 M HOCl. What is the pH of this solution? [Ka(HOCl) = 3.2 * 10-8]

Accepted Answer

A)  4.10
B)  7.00
C)  7.19
D)  7.49
E)  7.80F) A) and E)
G) C) and D)

Question 17

Find the concentration of calcium ions in a solution made by adding 3.50 g of calcium fluoride to 750. mL of 0.125 M NaF. [For CaF2, Ksp = 3.95 * 10-11.]

Accepted Answer

A)  3.16 * 10-10 M
B)  2.53 * 10-9 M
C)  4.29 * 10-4 M
D)  6.32 * 10-10 M
E)  2.15 * 10-4 MF) B) and C)
G) D) and E)

Question 18

Assuming equal concentrations of conjugate base and acid, which one of the following mixtures is suitable for making a buffer solution with an optimum pH of 9.2-9.3?

Accepted Answer

A)  CH3COONa / CH3COOH (Ka = 1.8 * 10-5) 
B)  NH3 / NH4Cl (Ka = 5.6 * 10-10) 
C)  NaOCl / HOCl (Ka = 3.2 * 10-8) 
D)  NaNO2 / HNO2 (Ka = 4.5 * 10-4) 
E)  NaCl / HClF) D) and E)
G) A) and E)

Question 19

What is the net ionic equation for the reaction that occurs when small amounts of hydrochloric acid are added to a HOCl/NaOCl buffer solution?

Accepted Answer

A)  H+ + H2O  →\rarr→  H3O+
B)  H+ + OCl-  →\rarr→  HOCl
C)  HOCl  →\rarr→  H+ + OCl-
D)  H+ + HOCl  →\rarr→  H2OCl+
E)  HCl + HOCl  →\rarr→  H2O + Cl2 F) B) and D)
G) All of the above

Question 20

The molar solubility of magnesium carbonate is 1.8 * 10-4 mol/L. What is Ksp for this compound?

Accepted Answer

A)  1.8 * 10-4
B)  3.6 * 10-4
C)  1.3 * 10-7
D)  3.2 * 10-8
E)  2.8 * 10-14F) A) and B)
G) None of the above

Exam 17: Acid-Base Equilibria and Solubility Equilibria

The molar solubility of tin(II) iodide is 1.28 * 10-2 mol/L. What is Ksp for this compound?

Correct AnswerverifiedShow Answer

Which of the following would decrease the Ksp for PbI2?

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Find the concentration of calcium ions in a solution made by adding 3.50 g of calcium fluoride to 750. mL of 0.125 M NaF. [For CaF2, Ksp = 3.95 * 10-11.]

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A solution is prepared by mixing 500. mL of 0.10 M NaOCl and 500. mL of 0.20 M HOCl. What is the pH of this solution? [Ka(HOCl) = 3.2 * 10-8]

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You are asked to go into the lab and prepare an acetic acid - sodium acetate buffer solution with a pH of 4.00 ± 0.02. What molar ratio of CH3COOH to CH3COONa should be used?

Correct AnswerverifiedShow Answer

Calculate the silver ion concentration in a saturated solution of silver(I) carbonate (Ksp = 8.1 * 10-12) .

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What mass of ammonium nitrate must be added to 350. mL of a 0.150 M solution of ammonia to give a buffer having a pH of 9.00? (Kb(NH3) = 1.8 * 10-5)

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Assuming equal concentrations of conjugate base and acid, which one of the following mixtures is suitable for making a buffer solution with an optimum pH of 9.2-9.3?

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An environmental chemist obtained a 200. mL sample of lake water believed to be contaminated with a single monoprotic strong acid. Titrating this sample with a 0.0050 M NaOH(aq)required 7.3 mL of the NaOH solution to reach the endpoint. What is the pH of the lake?

Correct AnswerverifiedShow Answer

A 50.0 mL sample of 2.0 * 10-4 M CuNO3 is added to 50.0 mL of 4.0 M NaCN. The formation constant of the complex ion Cu(CN)32- is 1.0 * 109. What is the copper(I)ion concentration in this system at equilibrium?

Correct Answerverified1.3 * 10View AnswerShow Answer

The solubility of a salt increases as its Ksp increases.

Correct AnswerverifiedShow Answer

Assuming equal concentrations of conjugate base and acid, which one of the following mixtures is suitable for making a buffer solution with an optimum pH of 4.6-4.8?

Correct AnswerverifiedShow Answer

Write an equation showing the net reaction that occurs when a strong acid is added to a CO32-/HCO3- buffer solution (for carbonic acid, Ka1 = 4.2 * 10-7, Ka2 = 2.4 * 10-8):

Correct AnswerverifiedCO32- +...View AnswerShow Answer

A saturated sodium carbonate solution at 100°C contains 45.5 g of dissolved sodium carbonate per 100. mL of solution. The solubility product constant for sodium carbonate at this temperature is

Correct AnswerverifiedShow Answer

NaCl is added slowly to a solution that is 0.010 M each in Cu+, Ag+, and Au+. The Ksp's for CuCl, AgCl, and AuCl are 1.9 * 10-7, 1.8 * 10-10, and 2.0 * 10-13, respectively. Which compound will precipitate first?

Correct AnswerverifiedShow Answer

The solubility product for calcium phosphate is Ksp = 1.3 * 10-26. What is the molar solubility of calcium phosphate?

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What is the pH at the equivalence point in the titration of 100 mL of 0.10 M HCl with 0.10 M NaOH?

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The molar solubility of magnesium carbonate is 1.8 * 10-4 mol/L. What is Ksp for this compound?

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Will a precipitate of magnesium fluoride form when 200. mL of 1.9 * 10-3 M MgCl2 are added to 300. mL of 1.4 * 10-2 M NaF? [Ksp (MgF2) = 6.9 * 10-9]

Correct AnswerverifiedShow Answer

What is the net ionic equation for the reaction that occurs when small amounts of hydrochloric acid are added to a HOCl/NaOCl buffer solution?

Correct AnswerverifiedShow Answer

The molar solubility of tin(II) iodide is 1.28 * 10^-2 mol/L. What is K_sp for this compound?

Correct Answer
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Which of the following would decrease the K_sp for PbI₂?

Correct Answer
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Find the concentration of calcium ions in a solution made by adding 3.50 g of calcium fluoride to 750. mL of 0.125 M NaF. [For CaF₂, K_sp = 3.95 * 10^-11.]

Correct Answer
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A solution is prepared by mixing 500. mL of 0.10 M NaOCl and 500. mL of 0.20 M HOCl. What is the pH of this solution? [K_a(HOCl) = 3.2 * 10^-8]

Correct Answer
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You are asked to go into the lab and prepare an acetic acid - sodium acetate buffer solution with a pH of 4.00 ± 0.02. What molar ratio of CH₃COOH to CH₃COONa should be used?

Correct Answer
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Calculate the silver ion concentration in a saturated solution of silver(I) carbonate (K_sp = 8.1 * 10^-12) .

Correct Answer
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What mass of ammonium nitrate must be added to 350. mL of a 0.150 M solution of ammonia to give a buffer having a pH of 9.00? (K_b(NH₃) = 1.8 * 10^-5)

Correct Answer
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Correct Answer
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Correct Answer
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A 50.0 mL sample of 2.0 * 10^-4 M CuNO₃ is added to 50.0 mL of 4.0 M NaCN. The formation constant of the complex ion Cu(CN)₃^2- is 1.0 * 10⁹. What is the copper(I)ion concentration in this system at equilibrium?

Correct Answer
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1.3 * 10
View Answer

The solubility of a salt increases as its K_sp increases.

Correct Answer
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Correct Answer
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Write an equation showing the net reaction that occurs when a strong acid is added to a CO₃^2-/HCO₃^- buffer solution (for carbonic acid, K_a1 = 4.2 * 10^-7, K_a2 = 2.4 * 10^-8):

Correct Answer
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CO₃^2- +...
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Correct Answer
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NaCl is added slowly to a solution that is 0.010 M each in Cu⁺, Ag⁺, and Au⁺. The K_sp's for CuCl, AgCl, and AuCl are 1.9 * 10^-7, 1.8 * 10^-10, and 2.0 * 10^-13, respectively. Which compound will precipitate first?

Correct Answer
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The solubility product for calcium phosphate is K_sp = 1.3 * 10^-26. What is the molar solubility of calcium phosphate?

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Correct Answer
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The molar solubility of magnesium carbonate is 1.8 * 10^-4 mol/L. What is K_sp for this compound?

Correct Answer
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Will a precipitate of magnesium fluoride form when 200. mL of 1.9 * 10^-3 M MgCl₂ are added to 300. mL of 1.4 * 10^-2 M NaF? [K_sp (MgF₂) = 6.9 * 10^-9]

Correct Answer
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Correct Answer
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