Question 1

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 NH3 
C) 0.10 mol L-1 HCl and 0.05 mol L-1 NH3 
D) 0.10 mol L-1 HCl and 0.20 mol L-1 CH3COOH 
E) 0.10 mol L-1 HCl and 0.20 mol L-1 NaCl 
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 NH3 
C) 0.10 mol L-1 HCl and 0.05 mol L-1 NH3 
D) 0.10 mol L-1 HCl and 0.20 mol L-1 CH3COOH 
E) 0.10 mol L-1 HCl and 0.20 mol L-1 NaCl

Question 2

The solubility of lead(II)chloride is 0.45 g/100 mL of solution.What is the Ksp of PbCl2?

Accepted Answer

A) 4.9 $\times$ 10-2 
B) 1.7 $\times$ 10-5 
C) 8.5 $\times$ 10-6 
D) 4.2 $\times$ 10-6 
E)  -6 
A) 4.9 $\times$ 10-2 
B) 1.7 $\times$ 10-5 
C) 8.5 $\times$ 10-6 
D) 4.2 $\times$ 10-6 
E)  -6

Question 3

A solution is prepared by adding 4.50 mol of sodium hydroxide to 1.00 L of 1.00 M Co(NO3)2.What is the equilibrium concentration of cobalt ions?
Kf = 5.0 $\times$ 109 for Co(OH)42-

Accepted Answer

A) 1.1 $\times$ 10-2 M 
B) 1.4 $\times$ 10-5 M 
C) 3.2 $\times$ 10-9 M 
D) 2.0 $\times$ 10-10 M 
E) 4.9 $\times$ 10-13 M 
A) 1.1 $\times$ 10-2 M 
B) 1.4 $\times$ 10-5 M 
C) 3.2 $\times$ 10-9 M 
D) 2.0 $\times$ 10-10 M 
E) 4.9 $\times$ 10-13 M

Question 4

A buffer is prepared by adding 1.00 L of 1.0 M HCl to 750 mL of 1.5 M NaHCOO.What is the pH of this buffer? Ka = 1.7 $\times$ 10-4

Accepted Answer

A) 2.87 
B) 3.72 
C) 3.82 
D) 3.95 
E) 4.66 
A) 2.87 
B) 3.72 
C) 3.82 
D) 3.95 
E) 4.66

Question 5

Hydrofluoric acid (HF)has a Ka value of 7.2 $\times$ 10-4.
a.0.250 mol of F- ions (in the form of NaF)are added to 1.00 L of 0.100 mol L-1 aqueous HF.Calculate the resulting pH.
b.To the solution produced in (a)is added 10.0 mL of 5.00 mol L-1 NaOH.Calculate the resulting pH.

Accepted Answer

The answer of Hydrofluoric acid (HF)has a Ka value of...

Question 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 $\times$ 10-4

Accepted Answer

A) 4.00 
B) 3.88 
C) 3.63 
D) 3.51 
E) 3.47 
A) 4.00 
B) 3.88 
C) 3.63 
D) 3.51 
E) 3.47

Question 7

Consider the dissolution of MnS in water (Ksp = 3.0 $\times$ 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?

Accepted Answer

A) The solubility will be unchanged. 
B) The solubility will decrease. 
C) The solubility will increase. 
D) The amount of KOH added must be known before its effect can be predicted. 
E) The pKa of H2S is needed before a reliable prediction can be made. 
A) The solubility will be unchanged. 
B) The solubility will decrease. 
C) The solubility will increase. 
D) The amount of KOH added must be known before its effect can be predicted. 
E) The pKa of H2S is needed before a reliable prediction can be made.

Question 8

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

Accepted Answer

A) True 
 B)False

Question 9

A CH3COOH/CH3COO- buffer can be produced by adding a strong acid to a solution of CH3COO- ions.

Accepted Answer

A) True 
 B)False

Question 10

What is the [H3O+] in a solution that consists of 1.2 M HClO and 2.3 M NaClO?
Ka = 3.5 $\times$ 10-8

Accepted Answer

A) 7.8 $\times$ 10-9 M 
B) 1.8 $\times$ 10-8 M 
C) 6.7 $\times$ 10-8 M 
D) 1.6 $\times$ 10-7 M 
E) None of these choices is correct. 
A) 7.8 $\times$ 10-9 M 
B) 1.8 $\times$ 10-8 M 
C) 6.7 $\times$ 10-8 M 
D) 1.6 $\times$ 10-7 M 
E) None of these choices is correct.

Question 11

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

Accepted Answer

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

Question 12

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

Accepted Answer

A) MgCO3,Ksp = 3.5 $\times$ 10-8 
B) NiCO3,Ksp = 1.3 $\times$ 10-7 
C) AgIO3,Ksp = 3.1 $\times$ 10-8 
D) CuBr,Ksp = 5.0 $\times$ 10-9 
E) AgCN,Ksp = 2.2 $\times$ 10-16 
A) MgCO3,Ksp = 3.5 $\times$ 10-8 
B) NiCO3,Ksp = 1.3 $\times$ 10-7 
C) AgIO3,Ksp = 3.1 $\times$ 10-8 
D) CuBr,Ksp = 5.0 $\times$ 10-9 
E) AgCN,Ksp = 2.2 $\times$ 10-16

Question 13

Make a clear distinction between buffer range and buffer capacity.

Accepted Answer

Buffer range is the range of pH over whi

Question 14

Silver phosphate,Ag3PO4,is an ionic compound with a solubility product constant Ksp of 2.6 $\times$ 10-18.Calculate the solubility of this compound in
a.pure water.
b.0.20 mol L-1 Na3PO4 solution.

Accepted Answer

a.1.8 @#LAT-DLM& 10^-5

Question 15

What is the pKa for the acid HA if a solution of 0.65 M HA and 0.85 M NaA has a pH of 4.75?

Accepted Answer

A)  5.50 
A)  5.50

Question 16

A lab technician adds 0.015 mol of KOH to 1.00 L of 0.0010 M Ca(NO3)2.Ksp = 6.5 $\times$ 10-6 for Ca(OH)2.Which of the following statements is correct?

Accepted Answer

A) Calcium hydroxide precipitates until the solution is saturated. 
B) The solution is unsaturated and no precipitate forms. 
C) The concentration of calcium ions is reduced by the addition of the hydroxide ions. 
D) One must know Ksp for calcium nitrate to make meaningful predictions on this system. 
E) The presence of KOH will raise the solubility of Ca(NO3)2. 
A) Calcium hydroxide precipitates until the solution is saturated. 
B) The solution is unsaturated and no precipitate forms. 
C) The concentration of calcium ions is reduced by the addition of the hydroxide ions. 
D) One must know Ksp for calcium nitrate to make meaningful predictions on this system. 
E) The presence of KOH will raise the solubility of Ca(NO3)2.

Question 17

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?

Accepted Answer

A) 1.1 $\times$ 10-7 
B) 3.5 $\times$ 10-8 
C) 1.2 $\times$ 10-8 
D) 4.9 $\times$ 10-11 
E) None of these choices is correct. 
A) 1.1 $\times$ 10-7 
B) 3.5 $\times$ 10-8 
C) 1.2 $\times$ 10-8 
D) 4.9 $\times$ 10-11 
E) None of these choices is correct.

Question 18

Calculate the solubility of silver oxalate,Ag2C2O4,in pure water.Ksp = 1.0 $\times$ 10-11

Accepted Answer

A) 1.4 $\times$ 10-4 M 
B) 8.2 $\times$ 10-5 M 
C) 5.4 $\times$ 10-5 M 
D) 3.2 $\times$ 10-6 M 
E) 2.5 $\times$ 10-12 M 
A) 1.4 $\times$ 10-4 M 
B) 8.2 $\times$ 10-5 M 
C) 5.4 $\times$ 10-5 M 
D) 3.2 $\times$ 10-6 M 
E) 2.5 $\times$ 10-12 M

Question 19

Which one of the following is the best representation of the titration curve which will be obtained in the titration of a weak base (0.10 mol L-1)with HCl of the same concentration?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
E) 
  
A) 
  
B) 
  
C) 
  
D) 
  
E)

Question 20

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

Accepted Answer

A) [H2PO4-] = 0.50 M,[HPO42-] = 0.50 M 
B) [H2PO4-] = 1.0 M,[HPO42-] = 1.0 M 
C) [H2PO4-] = 1.0 M,[HPO42-] = 0.50 M 
D) [H2PO4-] = 0.50 M,[HPO42-] = 1.0 M 
E) [H2PO4-] = 0.75 M,[HPO42-] = 1.0 M 
A) [H2PO4-] = 0.50 M,[HPO42-] = 0.50 M 
B) [H2PO4-] = 1.0 M,[HPO42-] = 1.0 M 
C) [H2PO4-] = 1.0 M,[HPO42-] = 0.50 M 
D) [H2PO4-] = 0.50 M,[HPO42-] = 1.0 M 
E) [H2PO4-] = 0.75 M,[HPO42-] = 1.0 M

Exam 19: Ionic Equilibria in Aqueous Systems

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

The solubility of lead(II)chloride is 0.45 g/100 mL of solution.What is the Ksp of PbCl2?

A solution is prepared by adding 4.50 mol of sodium hydroxide to 1.00 L of 1.00 M Co(NO3)2.What is the equilibrium concentration of cobalt ions? Kf = 5.0 ×\times× 109 for Co(OH)42-

A buffer is prepared by adding 1.00 L of 1.0 M HCl to 750 mL of 1.5 M NaHCOO.What is the pH of this buffer? Ka = 1.7 ×\times× 10-4

Hydrofluoric acid (HF)has a Ka value of 7.2 ×\times× 10-4. a.0.250 mol of F- ions (in the form of NaF)are added to 1.00 L of 0.100 mol L-1 aqueous HF.Calculate the resulting pH. b.To the solution produced in (a)is added 10.0 mL of 5.00 mol L-1 NaOH.Calculate the resulting pH.

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 ×\times× 10-4

Consider the dissolution of MnS in water (Ksp = 3.0 ×\times× 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?

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

A CH3COOH/CH3COO- buffer can be produced by adding a strong acid to a solution of CH3COO- ions.

What is the [H3O+] in a solution that consists of 1.2 M HClO and 2.3 M NaClO? Ka = 3.5 ×\times× 10-8

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

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

Make a clear distinction between buffer range and buffer capacity.

Silver phosphate,Ag3PO4,is an ionic compound with a solubility product constant Ksp of 2.6 ×\times× 10-18.Calculate the solubility of this compound in a.pure water. b.0.20 mol L-1 Na3PO4 solution.

What is the pKa for the acid HA if a solution of 0.65 M HA and 0.85 M NaA has a pH of 4.75?

A lab technician adds 0.015 mol of KOH to 1.00 L of 0.0010 M Ca(NO3)2.Ksp = 6.5 ×\times× 10-6 for Ca(OH)2.Which of the following statements is correct?

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?

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

Which one of the following is the best representation of the titration curve which will be obtained in the titration of a weak base (0.10 mol L-1)with HCl of the same concentration?

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

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids,solids,and Phase Changes

The Properties of Solutions

The Main-Group Elements: Applying Principles of Bonding and Structure

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Thermodynamics: Entropy, free Energy, and the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

The solubility of lead(II)chloride is 0.45 g/100 mL of solution.What is the K_sp of PbCl₂?

A solution is prepared by adding 4.50 mol of sodium hydroxide to 1.00 L of 1.00 M Co(NO₃)₂.What is the equilibrium concentration of cobalt ions? K_f = 5.0 $\times$ 10⁹ for Co(OH)₄^2-

A buffer is prepared by adding 1.00 L of 1.0 M HCl to 750 mL of 1.5 M NaHCOO.What is the pH of this buffer? K_a = 1.7 $\times$ 10^-4

Hydrofluoric acid (HF)has a K_a value of 7.2 $\times$ 10^-4. a.0.250 mol of F^- ions (in the form of NaF)are added to 1.00 L of 0.100 mol L^-1 aqueous HF.Calculate the resulting pH. b.To the solution produced in (a)is added 10.0 mL of 5.00 mol L^-1 NaOH.Calculate the resulting pH.

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 $\times$ 10^-4

A CH₃COOH/CH₃COO^- buffer can be produced by adding a strong acid to a solution of CH₃COO^- ions.

What is the [H₃O⁺] in a solution that consists of 1.2 M HClO and 2.3 M NaClO? K_a = 3.5 $\times$ 10^-8

Calculate the solubility of zinc hydroxide,Zn(OH)₂,in 1.00 M NaOH. K_sp = 3.0 $\times$ 10^-16 for Zn(OH)₂,K_f = 3.0 $\times$ 10¹⁵ for Zn(OH)₄^2-

Silver phosphate,Ag₃PO₄,is an ionic compound with a solubility product constant K_sp of 2.6 $\times$ 10^-18.Calculate the solubility of this compound in a.pure water. b.0.20 mol L^-1 Na₃PO₄ solution.

What is the pK_a for the acid HA if a solution of 0.65 M HA and 0.85 M NaA has a pH of 4.75?

A lab technician adds 0.015 mol of KOH to 1.00 L of 0.0010 M Ca(NO₃)₂.K_sp = 6.5 $\times$ 10^-6 for Ca(OH)₂.Which of the following statements is correct?

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?

Calculate the solubility of silver oxalate,Ag₂C₂O₄,in pure water.K_sp = 1.0 $\times$ 10^-11

Which one of the following is the best representation of the titration curve which will be obtained in the titration of a weak base (0.10 mol L^-1)with HCl of the same concentration?