Question 1

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 M 
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 M

Question 2

Calculate the solubility of barium carbonate, BaCO3, in pure water. Ksp = 2.0 × 10-9

Accepted Answer

A)  1.3 × 10-3 M 
B)  3.2 × 10-5 M 
C)  2.2 × 10-5 M 
D)  4.5 × 10-5 M 
E)  4.0 × 10-18 M 
A)  1.3 × 10-3 M 
B)  3.2 × 10-5 M 
C)  2.2 × 10-5 M 
D)  4.5 × 10-5 M 
E)  4.0 × 10-18 M

Question 3

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

Question 4

The indicator propyl red has Ka = 3.3 × 10-6. What would be the approximate pH range over which it would change color?

Accepted Answer

A)  3.5-5.5 
B)  4.5-6.5 
C)  5.5-7.5 
D)  6.5-8.5 
E)  none of the above 
A)  3.5-5.5 
B)  4.5-6.5 
C)  5.5-7.5 
D)  6.5-8.5 
E)  none of the above

Question 5

A 25.0-mL sample of 1.00 M NH3 is titrated with 0.15 M HCl. What is the pH of the solution after 15.00 mL of acid have been added to the ammonia solution? Kb = 1.8 × 10-5

Accepted Answer

A)  10.26 
B)  9.30 
C)  9.21 
D)  8.30 
E)  8.21 
A)  10.26 
B)  9.30 
C)  9.21 
D)  8.30 
E)  8.21

Question 6

Hydrochloric acid (0.100 mol L-1, 25.00 mL aliquot) is being titrated with sodium hydroxide of the same molarity. Calculate the solution pH after addition of 24.80 mL of the sodium hydroxide. Make any reasonable approximations.

Accepted Answer

Question 7

The solubility of salt MX (solubility product constant Ksp) in water will always be greater than that of salt MX3 (solubility product constant KF1F1F1S1F1F1F10sp) provided that Ksp > KF1F1F1S1F1F1F10sp.

Accepted Answer

A) True 
 B)False

Question 8

A buffer is to be prepared by adding solid sodium acetate to 0.10 M CH3COOH. Which of the following concentrations of sodium acetate will produce the most effective buffer?

Accepted Answer

A)  3.0 M CH3COONa 
B)  2.5 M CH3COONa 
C)  2.0 M CH3COONa 
D)  1.5 M CH3COONa 
E)  0.30 M CH3COONa 
A)  3.0 M CH3COONa 
B)  2.5 M CH3COONa 
C)  2.0 M CH3COONa 
D)  1.5 M CH3COONa 
E)  0.30 M CH3COONa

Question 9

A diprotic acid H2A has Ka1 = 1 × 10-4 and Ka2 = 1 × 10-8. The corresponding base A2- is titrated with aqueous HCl, both solutions being 0.1 mol L-1. Which one of the following diagrams best represents the titration curve which will be seen?

Accepted Answer

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

Question 10

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 11

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

Accepted Answer

A)  [CH3COOH] = 0.25 M, [CH3COO-] = 0.25 M 
B)  [CH3COOH] = 0.75 M, [CH3COO-] = 0.75 M 
C)  [CH3COOH] = 0.75 M, [CH3COO-] = 0.25 M 
D)  [CH3COOH] = 0.25 M, [CH3COO-] = 0.75 M 
E)  [CH3COOH] = 1.00 M, [CH3COO-] = 1.00 M 
A)  [CH3COOH] = 0.25 M, [CH3COO-] = 0.25 M 
B)  [CH3COOH] = 0.75 M, [CH3COO-] = 0.75 M 
C)  [CH3COOH] = 0.75 M, [CH3COO-] = 0.25 M 
D)  [CH3COOH] = 0.25 M, [CH3COO-] = 0.75 M 
E)  [CH3COOH] = 1.00 M, [CH3COO-] = 1.00 M

Question 12

A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH3COOH. What is the pH of this buffer? Ka = 1.8 × 10-5

Accepted Answer

A)  4.57 
B)  4.52 
C)  4.87 
D)  4.92 
E)  4.97 
A)  4.57 
B)  4.52 
C)  4.87 
D)  4.92 
E)  4.97

Question 13

Propanoic acid (CH3CH2COOH) has a Ka of 1.34 × 10-5. A 25.00 mL sample of 0.1000 mol L-1 propanoic acid (in flask) is titrated with 0.1000 mol L-1 NaOH solution, added from a buret. Carry out the calculations of the quantities indicated below.
a. The pH after 0.00 mL of NaOH are added.
b. The pH after 15.00 mL of NaOH are added.
c. The hydroxide ion concentration after 26.00 mL of NaOH are added.

Accepted Answer

a. 2.94
b.

Question 14

You need to use KH2PO4 and K2HPO4 to prepare a buffer with a pH of 7.45. Which of the following ratios of [base]/[acid] is required? For phosphoric acid, (H3PO4), Ka2 = 6.2 × 10-8.

Accepted Answer

A)  [base]/[acid] = 1.75 
B)  [base]/[acid] = 1.27 
C)  [base]/[acid] = 1.24 
D)  [base]/[acid] = 0.79 
E)  [base]/[acid] = 0.57 
A)  [base]/[acid] = 1.75 
B)  [base]/[acid] = 1.27 
C)  [base]/[acid] = 1.24 
D)  [base]/[acid] = 0.79 
E)  [base]/[acid] = 0.57

Question 15

Two buffer solutions are prepared using acetic acid and sodium acetate. Solution A contains 20.0 g of acetic acid (CH3COOH) and 5.0 g of sodium acetate CH3COONa). Solution B contains 10.0 g of acetic acid and 25.0 g of sodium acetate. What is the difference between the pH values of these two solutions? For acetic acid, Ka = 1.8 × 10-5.

Accepted Answer

A)  0.0 
B)  1.0 
C)  2.0 
D)  2.3 
E)  4.6 
A)  0.0 
B)  1.0 
C)  2.0 
D)  2.3 
E)  4.6

Question 16

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

Accepted Answer

A)  Ba(IO3)2, Ksp = 1.5 × 10-9 
B)  PbF2, Ksp = 3.6 × 10-8 
C)  SrSO4, Ksp = 3.2 × 10-7 
D)  CuCl, Ksp = 1.9 × 10-7 
E)  CdS, Ksp = 1.0 × 10-24 
A)  Ba(IO3)2, Ksp = 1.5 × 10-9 
B)  PbF2, Ksp = 3.6 × 10-8 
C)  SrSO4, Ksp = 3.2 × 10-7 
D)  CuCl, Ksp = 1.9 × 10-7 
E)  CdS, Ksp = 1.0 × 10-24

Question 17

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

Accepted Answer

A) True 
 B)False

Question 18

Calculate the solubility of zinc hydroxide, Zn(OH)2, in 1.00 M NaOH. Ksp = 3.0 × 10-16 for Zn(OH)2, Kf = 3.0 × 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 19

A popular buffer solution consists of carbonate (CO32-) and hydrogen carbonate (HCO3-) conjugate acid-base pair. Which, if any, of the following such buffers has the highest buffer capacity?

Accepted Answer

A)  0.9 M CO32- and 0.1 M HCO3- 
B)  0.1 M CO32- and 0.9 M HCO3- 
C)  0.5 M CO32- and 0.5 M HCO3- 
D)  0.1 M CO32- and 0.1 M HCO3- 
E)  They all have the same buffer capacity. 
A)  0.9 M CO32- and 0.1 M HCO3- 
B)  0.1 M CO32- and 0.9 M HCO3- 
C)  0.5 M CO32- and 0.5 M HCO3- 
D)  0.1 M CO32- and 0.1 M HCO3- 
E)  They all have the same buffer capacity.

Question 20

What is the maximum mass of KCl that can be added to1.0 L of a 0.010 M lead(II) chloride solution without causing any precipitation of lead(II) chloride? Assume that addition of KCl does not affect the solution volume. For lead(II) chloride, Ksp = 1.6 × 10-5 .

Accepted Answer

A)  3.0 g 
B)  1.5 g 
C)  0.8 g 
D)  1.0 g 
E)  0.2 g 
A)  3.0 g 
B)  1.5 g 
C)  0.8 g 
D)  1.0 g 
E)  0.2 g

Exam 19: Ionic Equilibria in Aqueous Systems

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

Calculate the solubility of barium carbonate, BaCO3, in pure water. Ksp = 2.0 × 10-9

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

The indicator propyl red has Ka = 3.3 × 10-6. What would be the approximate pH range over which it would change color?

A 25.0-mL sample of 1.00 M NH3 is titrated with 0.15 M HCl. What is the pH of the solution after 15.00 mL of acid have been added to the ammonia solution? Kb = 1.8 × 10-5

Hydrochloric acid (0.100 mol L-1, 25.00 mL aliquot) is being titrated with sodium hydroxide of the same molarity. Calculate the solution pH after addition of 24.80 mL of the sodium hydroxide. Make any reasonable approximations.

The solubility of salt MX (solubility product constant Ksp) in water will always be greater than that of salt MX3 (solubility product constant Ksp) provided that Ksp > Ksp.

A buffer is to be prepared by adding solid sodium acetate to 0.10 M CH3COOH. Which of the following concentrations of sodium acetate will produce the most effective buffer?

A diprotic acid H2A has Ka1 = 1 × 10-4 and Ka2 = 1 × 10-8. The corresponding base A2- is titrated with aqueous HCl, both solutions being 0.1 mol L-1. Which one of the following diagrams best represents the titration curve which will be seen?

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

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

A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH3COOH. What is the pH of this buffer? Ka = 1.8 × 10-5

You need to use KH2PO4 and K2HPO4 to prepare a buffer with a pH of 7.45. Which of the following ratios of [base]/[acid] is required? For phosphoric acid, (H3PO4), Ka2 = 6.2 × 10-8.

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

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

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

A popular buffer solution consists of carbonate (CO32-) and hydrogen carbonate (HCO3-) conjugate acid-base pair. Which, if any, of the following such buffers has the highest buffer capacity?

What is the maximum mass of KCl that can be added to1.0 L of a 0.010 M lead(II) chloride solution without causing any precipitation of lead(II) chloride? Assume that addition of KCl does not affect the solution volume. For lead(II) chloride, Ksp = 1.6 × 10-5 .

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

The 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 Mixtures: Solutions and Colloids

Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

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 Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

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

Calculate the solubility of barium carbonate, BaCO₃, in pure water. K_sp = 2.0 × 10^-9

The indicator propyl red has K_a = 3.3 × 10^-6. What would be the approximate pH range over which it would change color?

A 25.0-mL sample of 1.00 M NH₃is titrated with 0.15 M HCl. What is the pH of the solution after 15.00 mL of acid have been added to the ammonia solution? K_b = 1.8 × 10^-5

Hydrochloric acid (0.100 mol L^-1, 25.00 mL aliquot) is being titrated with sodium hydroxide of the same molarity. Calculate the solution pH after addition of 24.80 mL of the sodium hydroxide. Make any reasonable approximations.

The solubility of salt MX (solubility product constant K_sp) in water will always be greater than that of salt MX₃ (solubility product constant K_sp) provided that K_sp > K_sp.

A buffer is to be prepared by adding solid sodium acetate to 0.10 M CH₃COOH. Which of the following concentrations of sodium acetate will produce the most effective buffer?

A diprotic acid H₂A has K_a1 = 1 × 10^-4 and K_a2 = 1 × 10^-8. The corresponding base A^2- is titrated with aqueous HCl, both solutions being 0.1 mol L^-1. Which one of the following diagrams best represents the titration curve which will be seen?

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

A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH₃COOH. What is the pH of this buffer? K_a = 1.8 × 10^-5

You need to use KH₂PO₄ and K₂HPO₄ to prepare a buffer with a pH of 7.45. Which of the following ratios of [base]/[acid] is required? For phosphoric acid, (H₃PO₄), K_a2 = 6.2 × 10^-8.

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

A popular buffer solution consists of carbonate (CO₃^2-) and hydrogen carbonate (HCO₃^-) conjugate acid-base pair. Which, if any, of the following such buffers has the highest buffer capacity?

What is the maximum mass of KCl that can be added to1.0 L of a 0.010 M lead(II) chloride solution without causing any precipitation of lead(II) chloride? Assume that addition of KCl does not affect the solution volume. For lead(II) chloride, K_sp = 1.6 × 10^-5.