Question 1

Which of the following compounds will have the highest molar solubility in pure water?

Accepted Answer

A) PbSO4, Ksp = 1.82 × 10-8 
B) MgCO3, Ksp = 6.82 × 10-6 
C) AgI, Ksp = 8.51 × 10-17 
D) PbS, Ksp = 9.04 × 10-29 
E) FeS, Ksp = 3.72 × 10-19 
A) PbSO4, Ksp = 1.82 × 10-8 
B) MgCO3, Ksp = 6.82 × 10-6 
C) AgI, Ksp = 8.51 × 10-17 
D) PbS, Ksp = 9.04 × 10-29 
E) FeS, Ksp = 3.72 × 10-19

Question 2

Which of the following is TRUE?

Accepted Answer

A) An effective buffer has a [base]/[acid] ratio in the range of 10 - 100. 
B) A buffer is most resistant to pH change when [acid] = [conjugate base]. 
C) An effective buffer has very small absolute concentrations of acid and conjugate base. 
D) The capacity of a buffer cannot be exceeded by adding too much strong base. It can only be exceeded by adding too much strong acid. 
E) A buffer has the best resistance to pH change when the buffer's pH is significantly lower than the pKa of the acid used to make the buffer solution. 
A) An effective buffer has a [base]/[acid] ratio in the range of 10 - 100. 
B) A buffer is most resistant to pH change when [acid] = [conjugate base]. 
C) An effective buffer has very small absolute concentrations of acid and conjugate base. 
D) The capacity of a buffer cannot be exceeded by adding too much strong base. It can only be exceeded by adding too much strong acid. 
E) A buffer has the best resistance to pH change when the buffer's pH is significantly lower than the pKa of the acid used to make the buffer solution.

Question 3

Sketch the titration curve for a monoprotic weak acid titrated with a strong base. Make sure to indicate the equivalence point (and whether it is acidic, basic, or neutral)and the buffer region.

Accepted Answer

See figure

Question 4

What is the pH of a buffer solution that is 0.211 mol L-1 in lactic acid and 0.111 mol L-1 in sodium lactate? The Ka of lactic acid is 1.4 × 10-4.

Accepted Answer

A) 14.28 
B) 10.43 
C) 5.48 
D) 3.57 
E) 4.13 
A) 14.28 
B) 10.43 
C) 5.48 
D) 3.57 
E) 4.13

Question 5

A 25.0 mL sample of 0.150 mol L-1 butanoic acid is titrated with a 0.150 mol L-1 NaOH solution. What is the pH before any base is added? Butanoic acid is monoprotic. The Ka of butanoic acid is 1.5 × 10-5.

Accepted Answer

A) 2.83 
B) 1.5 × 10-3 
C) 4.82 
D) 4.00 
E) 1.0 × 104 
A) 2.83 
B) 1.5 × 10-3 
C) 4.82 
D) 4.00 
E) 1.0 × 104

Question 6

What happens at high pH to aluminum hydroxide precipitate?

Accepted Answer

A) Al(H2O)63+ is formed and the precipitate dissolves. 
B) Al(H2O)2(OH)4- is formed and the precipitate dissolves. 
C) Al(OH)3 precipitate still remains. 
D) Al precipitates. 
E) Al is formed. 
A) Al(H2O)63+ is formed and the precipitate dissolves. 
B) Al(H2O)2(OH)4- is formed and the precipitate dissolves. 
C) Al(OH)3 precipitate still remains. 
D) Al precipitates. 
E) Al is formed.

Question 7

Determine the molar solubility of CuCl in a solution containing 0.050 mol L-1 KCl. Ksp (CuCl)= 1.0 × 10-6.

Accepted Answer

A) 1.0 × 10-12 mol L-1 
B) 5.0 × 10-7 mol L-1 
C) 2.0 × 10-5 mol L-1 
D) 1.0 × 10-3 mol L-1 
E) 0.050 mol L-1 
A) 1.0 × 10-12 mol L-1 
B) 5.0 × 10-7 mol L-1 
C) 2.0 × 10-5 mol L-1 
D) 1.0 × 10-3 mol L-1 
E) 0.050 mol L-1

Question 8

Explain the common ion effect with respect to molar solubility.

Accepted Answer

The common ion effect occurs when a solu

Question 9

Determine the molar solubility of BaF2 in pure water. Ksp for BaF2 = 2.45 × 10-5.

Accepted Answer

A) 1.83 × 10-2 mol L-1 
B) 1.23 × 10-5 mol L-1 
C) 2.90 × 10-2 mol L-1 
D) 4.95 × 10-3 mol L-1 
E) 6.13 × 10-6 mol L-1 
A) 1.83 × 10-2 mol L-1 
B) 1.23 × 10-5 mol L-1 
C) 2.90 × 10-2 mol L-1 
D) 4.95 × 10-3 mol L-1 
E) 6.13 × 10-6 mol L-1

Question 10

Match the following.

-pH > 7

Accepted Answer

A) equivalence point of a weak base-strong acid titration 
B) equivalence point of a weak acid-strong base titration 
C) three-quarters of the way to second equivalence point of a diprotic acid-strong base titration 
D) halfway to equivalence point of a weak acid-strong base titration 
E) equivalence point of a strong acid-strong base titration 
A) equivalence point of a weak base-strong acid titration 
B) equivalence point of a weak acid-strong base titration 
C) three-quarters of the way to second equivalence point of a diprotic acid-strong base titration 
D) halfway to equivalence point of a weak acid-strong base titration 
E) equivalence point of a strong acid-strong base titration

Question 11

What happens at low pH to aluminum hydroxide precipitate?

Accepted Answer

A) Al(H2O)63+ is formed and the Al(OH)3 precipitate dissolves. 
B) Al(H2O)2(OH)4- is formed and the precipitate dissolves. 
C) Al(OH)3 precipitate is still present. 
D) Al precipitates. 
E) Al forms. 
A) Al(H2O)63+ is formed and the Al(OH)3 precipitate dissolves. 
B) Al(H2O)2(OH)4- is formed and the precipitate dissolves. 
C) Al(OH)3 precipitate is still present. 
D) Al precipitates. 
E) Al forms.

Question 12

What happens at neutral pH to aluminum hydroxide precipitate?

Accepted Answer

A) Al(H2O)63+ is formed and the precipitate dissolves. 
B) Al(H2O)2(OH)4- is formed and the precipitate dissolves. 
C) Al(OH)3 precipitate is still present. 
D) Al precipitates. 
E) Al is formed. 
A) Al(H2O)63+ is formed and the precipitate dissolves. 
B) Al(H2O)2(OH)4- is formed and the precipitate dissolves. 
C) Al(OH)3 precipitate is still present. 
D) Al precipitates. 
E) Al is formed.

Question 13

A solution contains 0.036 mol L-1 Cu2+ and 0.044 mol L-1 Fe2+. A solution containing sulfide ions is added to selectively precipitate one of the metal ions from solution. At what concentration of sulfide ion will a precipitate begin to form? What is the identity of the precipitate? Ksp(CuS)= 1.3 × 10-36, Ksp(FeS)= 6.3 × 10-18.

Accepted Answer

A) 1.4 × 10-16 mol L-1, FeS 
B) 3.6 × 10-35 mol L-1, CuS 
C) 3.6 × 10-35 mol L-1, FeS 
D) 1.4 × 10-16 mol L-1, CuS 
E) 1.4 × 10-16 mol L-1, both CuS and FeS will precipitate 
A) 1.4 × 10-16 mol L-1, FeS 
B) 3.6 × 10-35 mol L-1, CuS 
C) 3.6 × 10-35 mol L-1, FeS 
D) 1.4 × 10-16 mol L-1, CuS 
E) 1.4 × 10-16 mol L-1, both CuS and FeS will precipitate

Question 14

A 100.0 mL sample of 0.10 mol L-1 NH3 is titrated with 0.10 mol L-1 HNO3. Determine the pH of the solution before the addition of any HNO3. The Kb of NH3 is 1.8 × 10-5.

Accepted Answer

A) 4.74 
B) 9.26 
C) 11.13 
D) 13.00 
E) 12.55 
A) 4.74 
B) 9.26 
C) 11.13 
D) 13.00 
E) 12.55

Question 15

Which of the following is the correct equation relating Q to Ksp for a saturated solution?

Accepted Answer

A) Q > Ksp 
B) Q sp 
C) Q = Ksp 
D) Q ≠ Ksp 
E) Q ≥ Ksp 
A) Q > Ksp 
B) Q sp 
C) Q = Ksp 
D) Q ≠ Ksp 
E) Q ≥ Ksp

Question 16

A 100.0 mL sample of 0.10 mol L-1 NH3 is titrated with 0.10 mol L-1 HNO3. Determine the pH of the solution after the addition of 200.0 mL of HNO3. The Kb of NH3 is 1.8 × 10-5.

Accepted Answer

A) 6.44 
B) 1.48 
C) 2.00 
D) 12.52 
E) 12.00 
A) 6.44 
B) 1.48 
C) 2.00 
D) 12.52 
E) 12.00

Question 17

What is the pH of a solution prepared by mixing 25.00 mL of 0.10 mol L-1 CH3COOH with 25.00 mL of 0.010 mol L-1 CH3COONa? Assume that the volume of the solutions are additive and that Ka = 1.8 × 10-5 for CH3COOH.

Accepted Answer

A) 2.87 
B) 3.74 
C) 4.75 
D) 5.74 
A) 2.87 
B) 3.74 
C) 4.75 
D) 5.74

Question 18

What is the pH of a solution prepared by mixing 50.00 mL of 0.10 mol L-1 NH3 with 5.00 mL of 0.10 mol L-1 NH4Cl? Assume that the volume of the solutions are additive and that Kb = 1.8 × 10-5 for NH3.

Accepted Answer

A) 8.25 
B) 9.28 
C) 10.26 
D) 11.13 
A) 8.25 
B) 9.28 
C) 10.26 
D) 11.13

Question 19

Identify the compound that is acid-insoluble.

Accepted Answer

A) PbCl2 
B) As2S3 
C) CoS 
D) Ca3(PO4)2 
E) NaCl 
A) PbCl2 
B) As2S3 
C) CoS 
D) Ca3(PO4)2 
E) NaCl

Question 20

What volume of 5.00 × 10-3 mol L-1 HNO3 is needed to titrate 80.00 mL of 5.00 × 10-3 mol L-1 Ca(OH)2 to the equivalence point?

Accepted Answer

A) 10.0 mL 
B) 40.0 mL 
C) 80.0 mL 
D) 160. mL 
A) 10.0 mL 
B) 40.0 mL 
C) 80.0 mL 
D) 160. mL

Exam 16: Aqueous Ionic Equilibrium

Which of the following compounds will have the highest molar solubility in pure water?

Which of the following is TRUE?

Sketch the titration curve for a monoprotic weak acid titrated with a strong base. Make sure to indicate the equivalence point (and whether it is acidic, basic, or neutral)and the buffer region.

What is the pH of a buffer solution that is 0.211 mol L-1 in lactic acid and 0.111 mol L-1 in sodium lactate? The Ka of lactic acid is 1.4 × 10-4.

A 25.0 mL sample of 0.150 mol L-1 butanoic acid is titrated with a 0.150 mol L-1 NaOH solution. What is the pH before any base is added? Butanoic acid is monoprotic. The Ka of butanoic acid is 1.5 × 10-5.

What happens at high pH to aluminum hydroxide precipitate?

Determine the molar solubility of CuCl in a solution containing 0.050 mol L-1 KCl. Ksp (CuCl)= 1.0 × 10-6.

Explain the common ion effect with respect to molar solubility.

Determine the molar solubility of BaF2 in pure water. Ksp for BaF2 = 2.45 × 10-5.

Match the following. -pH > 7

What happens at low pH to aluminum hydroxide precipitate?

What happens at neutral pH to aluminum hydroxide precipitate?

A 100.0 mL sample of 0.10 mol L-1 NH3 is titrated with 0.10 mol L-1 HNO3. Determine the pH of the solution before the addition of any HNO3. The Kb of NH3 is 1.8 × 10-5.

Which of the following is the correct equation relating Q to Ksp for a saturated solution?

A 100.0 mL sample of 0.10 mol L-1 NH3 is titrated with 0.10 mol L-1 HNO3. Determine the pH of the solution after the addition of 200.0 mL of HNO3. The Kb of NH3 is 1.8 × 10-5.

What is the pH of a solution prepared by mixing 25.00 mL of 0.10 mol L-1 CH3COOH with 25.00 mL of 0.010 mol L-1 CH3COONa? Assume that the volume of the solutions are additive and that Ka = 1.8 × 10-5 for CH3COOH.

What is the pH of a solution prepared by mixing 50.00 mL of 0.10 mol L-1 NH3 with 5.00 mL of 0.10 mol L-1 NH4Cl? Assume that the volume of the solutions are additive and that Kb = 1.8 × 10-5 for NH3.

Identify the compound that is acid-insoluble.

What volume of 5.00 × 10-3 mol L-1 HNO3 is needed to titrate 80.00 mL of 5.00 × 10-3 mol L-1 Ca(OH)2 to the equivalence point?

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What is the pH of a buffer solution that is 0.211 mol L^-1 in lactic acid and 0.111 mol L^-1 in sodium lactate? The K_a of lactic acid is 1.4 × 10^-4.

A 25.0 mL sample of 0.150 mol L^-1 butanoic acid is titrated with a 0.150 mol L^-1 NaOH solution. What is the pH before any base is added? Butanoic acid is monoprotic. The K_a of butanoic acid is 1.5 × 10^-5.

Determine the molar solubility of CuCl in a solution containing 0.050 mol L^-1 KCl. K_sp (CuCl)= 1.0 × 10^-6.

Determine the molar solubility of BaF₂in pure water. K_sp for BaF₂ = 2.45 × 10^-5.

A 100.0 mL sample of 0.10 mol L^-1 NH₃ is titrated with 0.10 mol L^-¹ HNO₃. Determine the pH of the solution before the addition of any HNO₃. The K_b of NH₃ is 1.8 × 10^-5.

Which of the following is the correct equation relating Q to K_sp for a saturated solution?

A 100.0 mL sample of 0.10 mol L^-1 NH₃ is titrated with 0.10 mol L^-1 HNO₃. Determine the pH of the solution after the addition of 200.0 mL of HNO₃. The K_b of NH₃ is 1.8 × 10^-5.

What is the pH of a solution prepared by mixing 25.00 mL of 0.10 mol L^-1 CH₃COOH with 25.00 mL of 0.010 mol L^-1 CH₃COONa? Assume that the volume of the solutions are additive and that K_a = 1.8 × 10^-5 for CH₃COOH.

What is the pH of a solution prepared by mixing 50.00 mL of 0.10 mol L^-1 NH₃ with 5.00 mL of 0.10 mol L^-1 NH₄Cl? Assume that the volume of the solutions are additive and that K_b = 1.8 × 10^-5for NH₃.

What volume of 5.00 × 10^-3 mol L^-1 HNO₃ is needed to titrate 80.00 mL of 5.00 × 10^-3 mol L^-1 Ca(OH)₂ to the equivalence point?