Question 1

Describe the solubility of Al(OH)3 with respect to pH.

Accepted Answer

A) soluble at low pH,insoluble in pH-neutral solution,and soluble at high pH 
B) soluble at low pH,insoluble in pH-neutral solution,and insoluble at high pH 
C) insoluble at low pH,insoluble in pH-neutral solution,and soluble at high pH 
D) soluble at low pH,in pH-neutral solution,and at high pH 
E) insoluble at low pH,in pH-neutral solution,and at high pH 
A) soluble at low pH,insoluble in pH-neutral solution,and soluble at high pH 
B) soluble at low pH,insoluble in pH-neutral solution,and insoluble at high pH 
C) insoluble at low pH,insoluble in pH-neutral solution,and soluble at high pH 
D) soluble at low pH,in pH-neutral solution,and at high pH 
E) insoluble at low pH,in pH-neutral solution,and at high pH A

Question 2

When titrating a monoprotic strong acid with a weak base at 25 °C,the

Accepted Answer

A) pH will be 7 at the equivalence point. 
B) pH will be greater than 7 at the equivalence point. 
C) titration will require more moles of base than acid to reach the equivalence point. 
D) titration will require more moles of acid than base to reach the equivalence point. 
E) pH will be less than 7 at the equivalence point. 
A) pH will be 7 at the equivalence point. 
B) pH will be greater than 7 at the equivalence point. 
C) titration will require more moles of base than acid to reach the equivalence point. 
D) titration will require more moles of acid than base to reach the equivalence point. 
E) pH will be less than 7 at the equivalence point. E

Question 3

Identify the salts that are in hard water.

Accepted Answer

A) CaCO3 and MgCO3 
B) MgSO4 and CaSO4 
C) NaCl and KBr 
D) NaHSO4 and Na2SO4 
E) NaOCl and HOCl 
A) CaCO3 and MgCO3 
B) MgSO4 and CaSO4 
C) NaCl and KBr 
D) NaHSO4 and Na2SO4 
E) NaOCl and HOCl A

Question 4

A sample contains Ba3(PO4)2, CdS,AgCl,NH4Cl,and ZnS.Identify the soluble salt remaining in the solution after the addition of 6 mol L-1 HCl,followed by the addition of H2S and 0.2 mol L-1 HCl,then the addition of OH- to a pH of 8,and finally the addition of (NH4)2HPO4 with NH3.

Accepted Answer

A) Ba3(PO4)2 
B) CdS 
C) AgCl 
D) NH4Cl 
E) ZnS 
A) Ba3(PO4)2 
B) CdS 
C) AgCl 
D) NH4Cl 
E) ZnS

Question 5

Which one of the following statements is TRUE?

Accepted Answer

A) A buffer is an aqueous solution composed of two weak acids. 
B) A buffer can absorb an unlimited amount of acid or base. 
C) A buffer resists pH change by neutralizing added acids and bases. 
D) A buffer does not change pH when large amounts of a strong acid or a strong base are added. 
E) The common ion in a buffer solution does not have any effect on the dissociation of the acidic component of the buffer solution. 
A) A buffer is an aqueous solution composed of two weak acids. 
B) A buffer can absorb an unlimited amount of acid or base. 
C) A buffer resists pH change by neutralizing added acids and bases. 
D) A buffer does not change pH when large amounts of a strong acid or a strong base are added. 
E) The common ion in a buffer solution does not have any effect on the dissociation of the acidic component of the buffer solution.

Question 6

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 7

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 8

Determine the molar solubility of PbSO4 in pure water.Ksp (PbSO4)= 1.82 × 10-8.

Accepted Answer

A) 1.82 × 10-8 mol L-1 
B) 1.35 × 10-4 mol L-1 
C) 9.10 × 10-9 mol L-1 
D) 3.31 × 10-16 mol L-1 
E) 4.48 × 10-4 mol L-1 
A) 1.82 × 10-8 mol L-1 
B) 1.35 × 10-4 mol L-1 
C) 9.10 × 10-9 mol L-1 
D) 3.31 × 10-16 mol L-1 
E) 4.48 × 10-4 mol L-1

Question 9

A 100.0 mL sample of 0.20 mol L-1 HF is titrated with 0.10 mol L-1 KOH.Determine the pH of the solution after the addition of 100.0 mL of KOH.The Ka of HF is 3.5 × 10-4.

Accepted Answer

A) 2.08 
B) 3.15 
C) 4.33 
D) 3.46 
E) 4.15 
A) 2.08 
B) 3.15 
C) 4.33 
D) 3.46 
E) 4.15

Question 10

Formic acid (HCOOH,Ka = 1.8 × 10-4)is the principal component in the venom of stinging ants.What is the molarity of a formic acid solution if 25.00 mL of the formic acid solution requires 29.80 mL of 0.0567 mol L-1 NaOH to reach the equivalence point?

Accepted Answer

A) 0.0134 mol L-1 
B) 0.0476 mol L-1 
C) 0.0567 mol L-1 
D) 0.0676 mol L-1 
A) 0.0134 mol L-1 
B) 0.0476 mol L-1 
C) 0.0567 mol L-1 
D) 0.0676 mol L-1

Question 11

Which of the following solutions is a good buffer system?

Accepted Answer

A) a solution that is 0.10 mol L-1 NaCl and 0.10 mol L-1 HCl 
B) a solution that is 0.10 mol L-1 HCN and 0.10 mol L-1 LiCN 
C) a solution that is 0.10 mol L-1 NaOH and 0.10 mol L-1 HNO3 
D) a solution that is 0.10 mol L-1 HNO3 and 0.10 mol L-1 KNO3 
E) a solution that is 0.10 mol L-1 HCN and 0.10 mol L-1 NaCl 
A) a solution that is 0.10 mol L-1 NaCl and 0.10 mol L-1 HCl 
B) a solution that is 0.10 mol L-1 HCN and 0.10 mol L-1 LiCN 
C) a solution that is 0.10 mol L-1 NaOH and 0.10 mol L-1 HNO3 
D) a solution that is 0.10 mol L-1 HNO3 and 0.10 mol L-1 KNO3 
E) a solution that is 0.10 mol L-1 HCN and 0.10 mol L-1 NaCl

Question 12

Calculate the pH of a buffer that is 0.105 mol L-1 CH3COOH and 0.146 mol L-1 CH3COOK.The Ka for CH3COOH is 1.8 × 10-5.

Accepted Answer

A) 4.89 
B) 9.11 
C) 4.74 
D) 9.26 
E) 4.60 
A) 4.89 
B) 9.11 
C) 4.74 
D) 9.26 
E) 4.60

Question 13

What is the hydronium ion concentration in a solution prepared by mixing 50.00 mL of 0.10 mol L-1 HCN with 50.00 mL of $0.030 \mathrm {~mol} \mathrm {~L} ^ { - 1 }$ NaCN? Assume that the volumes of the solutions are additive and that Ka = $4.9 \times 10 ^{- 10} \text { for } \mathrm { HCN } \text {. }$

Accepted Answer

A) 1.5 × 10-10 mol L-1 
B) 4.9 × 10-10 mol L-1 
C) 1.6 × 10-9 mol L-1 
D) 7.0 × 10-6 mol L-1 
A) 1.5 × 10-10 mol L-1 
B) 4.9 × 10-10 mol L-1 
C) 1.6 × 10-9 mol L-1 
D) 7.0 × 10-6 mol L-1

Question 14

Calculate the pH of a solution formed by mixing 200.0 mL of 0.30 mol L-1 HClO with 100.0 mL of 0.20 mol L-1 KClO.The Ka for HClO is 2.9 × 10-8.

Accepted Answer

A) 5.99 
B) 8.01 
C) 7.54 
D) 7.06 
E) 6.46 
A) 5.99 
B) 8.01 
C) 7.54 
D) 7.06 
E) 6.46

Question 15

A solution contains 0.021 mol L-1 Cl- and 0.017 mol L-1 I-.A solution containing copper(I)ions is added to selectively precipitate one of the ions.At what concentration of copper(I)ion will a precipitate begin to form? What is the identity of the precipitate? Ksp(CuCl)= 1.0 × 10-6,Ksp(CuI)= 5.1 × 10-12.

Accepted Answer

A) 3.0 × 10-10 mol L-1,CuI 
B) 3.0 × 10-10 mol L-1,CuCl 
C) 4.8 × 10-5 mol L-1,CuCl 
D) 4.8 × 10-5 mol L-1,CuI 
E) 3.0 × 10-5 mol L-1,both CuCl and CuI are in the precipitate 
A) 3.0 × 10-10 mol L-1,CuI 
B) 3.0 × 10-10 mol L-1,CuCl 
C) 4.8 × 10-5 mol L-1,CuCl 
D) 4.8 × 10-5 mol L-1,CuI 
E) 3.0 × 10-5 mol L-1,both CuCl and CuI are in the precipitate

Question 16

A 100.0 mL sample of 0.20 mol L-1 HF is titrated with 0.10 mol L-1 KOH.Determine the pH of the solution after the addition of 400.0 mL of KOH.The Ka of HF is 3.5 × 10-4.

Accepted Answer

A) 13.08 
B) 12.60 
C) 13.85 
D) 12.30 
E) 12.78 
A) 13.08 
B) 12.60 
C) 13.85 
D) 12.30 
E) 12.78

Question 17

What is the pH of a solution made by mixing 40.00 mL of 0.100 mol L-1 HCl with 25.00 mL of 0.100 mol L-1 KOH? Assume that the volumes of the solutions are additive.

Accepted Answer

A) 0.64 
B) 1.64 
C) 12.36 
D) 13.36 
E) 10.00 
A) 0.64 
B) 1.64 
C) 12.36 
D) 13.36 
E) 10.00

Question 18

Which of the following is the correct equation relating Q to Ksp for an unsaturated 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 19

A 1.50 L buffer solution is 0.250 mol L-1 in HF and 0.250 mol L-1 in NaF.Calculate the pH of the solution after the addition of 0.0500 moles of solid NaOH.Assume no volume change upon the addition of the base.The Ka for HF is 3.5 × 10-4.

Accepted Answer

A) 3.34 
B) 3.46 
C) 3.57 
D) 3.63 
E) 2.89 
A) 3.34 
B) 3.46 
C) 3.57 
D) 3.63 
E) 2.89

Question 20

Calculate the pH of a buffer that is 0.020 mol L-1 HF and 0.040 mol L-1 LiF.The Ka for HF is 3.5 × 10-4.

Accepted Answer

A) 2.06 
B) 4.86 
C) 3.16 
D) 3.46 
E) 3.76 
A) 2.06 
B) 4.86 
C) 3.16 
D) 3.46 
E) 3.76

Exam 16: Aqueous Ionic Equilibrium

Describe the solubility of Al(OH)3 with respect to pH.

When titrating a monoprotic strong acid with a weak base at 25 °C,the

Identify the salts that are in hard water.

A sample contains Ba3(PO4)2, CdS,AgCl,NH4Cl,and ZnS.Identify the soluble salt remaining in the solution after the addition of 6 mol L-1 HCl,followed by the addition of H2S and 0.2 mol L-1 HCl,then the addition of OH- to a pH of 8,and finally the addition of (NH4)2HPO4 with NH3.

Which one of the following statements is TRUE?

What happens at neutral pH to aluminum hydroxide precipitate?

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

Determine the molar solubility of PbSO4 in pure water.Ksp (PbSO4)= 1.82 × 10-8.

A 100.0 mL sample of 0.20 mol L-1 HF is titrated with 0.10 mol L-1 KOH.Determine the pH of the solution after the addition of 100.0 mL of KOH.The Ka of HF is 3.5 × 10-4.

Formic acid (HCOOH,Ka = 1.8 × 10-4)is the principal component in the venom of stinging ants.What is the molarity of a formic acid solution if 25.00 mL of the formic acid solution requires 29.80 mL of 0.0567 mol L-1 NaOH to reach the equivalence point?

Which of the following solutions is a good buffer system?

Calculate the pH of a buffer that is 0.105 mol L-1 CH3COOH and 0.146 mol L-1 CH3COOK.The Ka for CH3COOH is 1.8 × 10-5.

Calculate the pH of a solution formed by mixing 200.0 mL of 0.30 mol L-1 HClO with 100.0 mL of 0.20 mol L-1 KClO.The Ka for HClO is 2.9 × 10-8.

A 100.0 mL sample of 0.20 mol L-1 HF is titrated with 0.10 mol L-1 KOH.Determine the pH of the solution after the addition of 400.0 mL of KOH.The Ka of HF is 3.5 × 10-4.

What is the pH of a solution made by mixing 40.00 mL of 0.100 mol L-1 HCl with 25.00 mL of 0.100 mol L-1 KOH? Assume that the volumes of the solutions are additive.

Which of the following is the correct equation relating Q to Ksp for an unsaturated solution?

A 1.50 L buffer solution is 0.250 mol L-1 in HF and 0.250 mol L-1 in NaF.Calculate the pH of the solution after the addition of 0.0500 moles of solid NaOH.Assume no volume change upon the addition of the base.The Ka for HF is 3.5 × 10-4.

Calculate the pH of a buffer that is 0.020 mol L-1 HF and 0.040 mol L-1 LiF.The Ka for HF is 3.5 × 10-4.

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Filters

Describe the solubility of Al(OH)₃ with respect to pH.

A sample contains Ba₃(PO₄)₂,CdS,AgCl,NH₄Cl,and ZnS.Identify the soluble salt remaining in the solution after the addition of 6 mol L^-1 HCl,followed by the addition of H₂S and 0.2 mol L^-1 HCl,then the addition of OH^-to a pH of 8,and finally the addition of (NH₄)₂HPO₄ with NH₃.

Determine the molar solubility of PbSO₄ in pure water.K_sp (PbSO₄)= 1.82 × 10^-8.

A 100.0 mL sample of 0.20 mol L^-1 HF is titrated with 0.10 mol L^-1 KOH.Determine the pH of the solution after the addition of 100.0 mL of KOH.The K_a of HF is 3.5 × 10^-4.

Formic acid (HCOOH,K_a = 1.8 × 10^-4)is the principal component in the venom of stinging ants.What is the molarity of a formic acid solution if 25.00 mL of the formic acid solution requires 29.80 mL of 0.0567 mol L^-1 NaOH to reach the equivalence point?

Calculate the pH of a buffer that is 0.105 mol L^-1 CH₃COOH and 0.146 mol L^-1 CH₃COOK.The K_a for CH₃COOH is 1.8 × 10^-5.

Calculate the pH of a solution formed by mixing 200.0 mL of 0.30 mol L^-1 HClO with 100.0 mL of 0.20 mol L^-1 KClO.The K_a for HClO is 2.9 × 10^-8.

A 100.0 mL sample of 0.20 mol L^-1 HF is titrated with 0.10 mol L^-1 KOH.Determine the pH of the solution after the addition of 400.0 mL of KOH.The K_a of HF is 3.5 × 10^-4.

What is the pH of a solution made by mixing 40.00 mL of 0.100 mol L^-1 HCl with 25.00 mL of 0.100 mol L^-1 KOH? Assume that the volumes of the solutions are additive.

Which of the following is the correct equation relating Q to K_sp for an unsaturated solution?

A 1.50 L buffer solution is 0.250 mol L^-1 in HF and 0.250 mol L^-1 in NaF.Calculate the pH of the solution after the addition of 0.0500 moles of solid NaOH.Assume no volume change upon the addition of the base.The K_a for HF is 3.5 × 10^-4.

Calculate the pH of a buffer that is 0.020 mol L^-1 HF and 0.040 mol L^-1 LiF.The K_a for HF is 3.5 × 10^-4.