Question 1

Calculate the solubility of magnesium sulfate, MgSO4, when placed into a 0.10 M MgCl2 solution. Ksp = 5.9 *10¯3

Accepted Answer

A)  4.2 * 10¯2 M 
B)  5.9 *10¯2 M 
C)  7.7 *10¯2 M 
D)  3.5 * 10¯5 M 
E)  3.5 * 10¯6 M 
A)  4.2 * 10¯2 M 
B)  5.9 *10¯2 M 
C)  7.7 *10¯2 M 
D)  3.5 * 10¯5 M 
E)  3.5 * 10¯6 M

Question 2

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 3

A 50.0-mL sample of 0.50 M HCl is titrated with 0.50 M NaOH. What is the pH of the solution after 28.0 mL of NaOH have been added to the acid?

Accepted Answer

A)  0.85 
B)  0.75 
C)  0.66 
D)  0.49 
E)  3.8 
A)  0.85 
B)  0.75 
C)  0.66 
D)  0.49 
E)  3.8

Question 4

A solution is prepared by mixing 50.0 mL of 0.50 M Cu(NO3)2 with 50.0 mL of 0.50 M Co(NO3)2. Sodium hydroxide is added to the mixture. Which hydroxide precipitates first and what concentration of hydroxide ions present in solution will accomplish the separation? Ksp = 2.2 *10¯20 for Cu(OH)2, Ksp = 1.3 *10¯15 for Co(OH)2

Accepted Answer

A)  Co(OH)2; [OH¯] = 6.9 * 10¯6 M 
B)  Co(OH)2; [OH¯] = 2.6 * 10¯7 M 
C)  Cu(OH)2; [OH¯] = 1.8 * 10¯7 M 
D)  Cu(OH)2; [OH¯] = 1.1 * 10¯9 M 
E)  Cu(OH)2; [OH¯] = 1.0 * 10¯17 M 
A)  Co(OH)2; [OH¯] = 6.9 * 10¯6 M 
B)  Co(OH)2; [OH¯] = 2.6 * 10¯7 M 
C)  Cu(OH)2; [OH¯] = 1.8 * 10¯7 M 
D)  Cu(OH)2; [OH¯] = 1.1 * 10¯9 M 
E)  Cu(OH)2; [OH¯] = 1.0 * 10¯17 M

Question 5

The concentration of the complex ion in each of following solutions is 1.00 M. In which of the solutions will the concentration of the uncomplexed metal ion be the greatest?

Accepted Answer

A)  Hg2+ 
B)  Be2+ 
C)  Zn2+ 
D)  Cu2+ 
E)  Cd2+ 
A)  Hg2+ 
B)  Be2+ 
C)  Zn2+ 
D)  Cu2+ 
E)  Cd2+

Question 6

Citric acid has an acid dissociation constant of 8.4 *10¯4. It would be most effective for preparation of a buffer with a pH of:

Accepted Answer

A)  2 
B)  3 
C)  4 
D)  5 
E)  6 
A)  2 
B)  3 
C)  4 
D)  5 
E)  6

Question 7

What is the pH of a buffer that consists of 0.20 M NaH2PO4 and 0.40 M Na2HPO4? For NaH2PO4, Ka = 6.2*10¯8

Accepted Answer

A)  6.51 
B)  6.91 
C)  7.51 
D)  7.90 
E)  8.13 
A)  6.51 
B)  6.91 
C)  7.51 
D)  7.90 
E)  8.13

Question 8

The solubility of silver chromate is 0.0287 g/1.0 L of solution. What is the Ksp for Ag2CrO4?

Accepted Answer

A)  9.5 * 10¯5 
B)  2.4 * 10¯5 
C)  2.6 * 10¯12 
D)  6.5 * 10¯13 
E)  13 
A)  9.5 * 10¯5 
B)  2.4 * 10¯5 
C)  2.6 * 10¯12 
D)  6.5 * 10¯13 
E)  13

Question 9

Calculate the solubility of zinc hydroxide, Zn(OH)2, in 1.00 M NaOH.

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 10

Increasing the concentrations of the components of a buffer solution will increase the buffer capacity.

Accepted Answer

A) True 
 B)False

Question 11

What is the [H3O+] in a buffer that consists of 0.30 M HCOOH and 0.20 M HCOONa? For HCOOH, Ka = 1.7 * 10¯4

Accepted Answer

A)  1.1 * 10¯4 M 
B)  2.6 *10¯4 M 
C)  4.3* 10¯4 M 
D)  6.7 *10¯5 M 
E)  None of these choices is correct. 
A)  1.1 * 10¯4 M 
B)  2.6 *10¯4 M 
C)  4.3* 10¯4 M 
D)  6.7 *10¯5 M 
E)  None of these choices is correct.

Question 12

What volume of 0.500 M H2SO4 is needed to react completely with 20.0 mL of 0.400 M LiOH?

Accepted Answer

A)  4.00 mL 
B)  8.00 mL 
C)  12.5 mL 
D)  16.0 mL 
E)  32.0 mL 
A)  4.00 mL 
B)  8.00 mL 
C)  12.5 mL 
D)  16.0 mL 
E)  32.0 mL

Question 13

An acetate buffer has a pH of 4.40. Which of the following changes will cause the pH to decrease?

Accepted Answer

A)  dissolving a small amount of solid sodium acetate 
B)  adding a small amount of dilute hydrochloric acid 
C)  adding a small amount of dilute sodium hydroxide 
D)  dissolving a small amount of solid sodium chloride 
E)  diluting the buffer solution with water 
A)  dissolving a small amount of solid sodium acetate 
B)  adding a small amount of dilute hydrochloric acid 
C)  adding a small amount of dilute sodium hydroxide 
D)  dissolving a small amount of solid sodium chloride 
E)  diluting the buffer solution with water

Question 14

A buffer is prepared by adding 100 mL of 0.50 M sodium hydroxide to 100 mL of 0.75 M propanoic acid. Is this a buffer solution, and if so, what is its pH?

Accepted Answer

A)  It is a buffer, pH > pKa of propanoic acid. 
B)  It is a buffer, pH a of propanoic acid. 
C)  It is a buffer, pH = pKa of propanoic acid. 
D)  It is a buffer, pH = pKb of sodium propanoate. 
E)  Since sodium hydroxide is a strong base, this is not a buffer. 
A)  It is a buffer, pH > pKa of propanoic acid. 
B)  It is a buffer, pH a of propanoic acid. 
C)  It is a buffer, pH = pKa of propanoic acid. 
D)  It is a buffer, pH = pKb of sodium propanoate. 
E)  Since sodium hydroxide is a strong base, this is not a buffer.

Question 15

Use the following information to calculate the solubility product constant, Ksp, for CuCl. A saturated solution of CuCl in water was prepared and filtered. From the filtrate, 1.0 L was measured out into a beaker and evaporated to dryness. The solid CuCl residue recovered in the beaker was found to weigh 0.041g.

Accepted Answer

A)  Ksp =1.7 *10¯9 
B)  Ksp = 1.7 *10¯7 
C)  Ksp = 1.7 *10¯5 
D)  Ksp = 4.3 *10¯4 
E)  Ksp = 2.1 *10¯2 
A)  Ksp =1.7 *10¯9 
B)  Ksp = 1.7 *10¯7 
C)  Ksp = 1.7 *10¯5 
D)  Ksp = 4.3 *10¯4 
E)  Ksp = 2.1 *10¯2

Question 16

A solution is prepared by adding 500 mL of 0.3 M NaClO to 500 mL of 0.4 M HClO. What is the pH of this solution?

Accepted Answer

A)  The pH will be greater than the pKa of hypochlorous acid. 
B)  The pH will be less than the pKa of hypochlorous acid. 
C)  The pH will be equal to the pKa of hypochlorous acid. 
D)  The pH will equal the pKb of sodium hypochlorite. 
E)  None of these choices is correct. 
A)  The pH will be greater than the pKa of hypochlorous acid. 
B)  The pH will be less than the pKa of hypochlorous acid. 
C)  The pH will be equal to the pKa of hypochlorous acid. 
D)  The pH will equal the pKb of sodium hypochlorite. 
E)  None of these choices is correct.

Question 17

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

Accepted Answer

A) True 
 B)False

Question 18

What will be the effect of adding 0.5 mL of 0.1 M NaOH to 100 mL of an acetate buffer in which [CH3COOH] = [CH3COO¯] = 0.5 M?

Accepted Answer

A)  The pH will increase slightly. 
B)  The pH will increase significantly. 
C)  The pH will decrease slightly. 
D)  The pH will decrease significantly. 
E)  Since it is a buffer solution, the pH will not be affected. 
A)  The pH will increase slightly. 
B)  The pH will increase significantly. 
C)  The pH will decrease slightly. 
D)  The pH will decrease significantly. 
E)  Since it is a buffer solution, the pH will not be affected.

Question 19

The solubility of aluminum hydroxide in water ______________ when dilute nitric acid is added to it.

Accepted Answer

A)  increases 
B)  decreases 
C)  does not change 
D)  first increases, then decreases 
E)  first decreases, then increases 
A)  increases 
B)  decreases 
C)  does not change 
D)  first increases, then decreases 
E)  first decreases, then increases

Question 20

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 * 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

Exam 19: Ionic Equilibria in Aqueous Systems

Calculate the solubility of magnesium sulfate, MgSO4, when placed into a 0.10 M MgCl2 solution. Ksp = 5.9 *10¯3

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?

A 50.0-mL sample of 0.50 M HCl is titrated with 0.50 M NaOH. What is the pH of the solution after 28.0 mL of NaOH have been added to the acid?

The concentration of the complex ion in each of following solutions is 1.00 M. In which of the solutions will the concentration of the uncomplexed metal ion be the greatest?

Citric acid has an acid dissociation constant of 8.4 *10¯4. It would be most effective for preparation of a buffer with a pH of:

What is the pH of a buffer that consists of 0.20 M NaH2PO4 and 0.40 M Na2HPO4? For NaH2PO4, Ka = 6.2*10¯8

The solubility of silver chromate is 0.0287 g/1.0 L of solution. What is the Ksp for Ag2CrO4?

Calculate the solubility of zinc hydroxide, Zn(OH)2, in 1.00 M NaOH.

Increasing the concentrations of the components of a buffer solution will increase the buffer capacity.

What is the [H3O+] in a buffer that consists of 0.30 M HCOOH and 0.20 M HCOONa? For HCOOH, Ka = 1.7 * 10¯4

What volume of 0.500 M H2SO4 is needed to react completely with 20.0 mL of 0.400 M LiOH?

An acetate buffer has a pH of 4.40. Which of the following changes will cause the pH to decrease?

A buffer is prepared by adding 100 mL of 0.50 M sodium hydroxide to 100 mL of 0.75 M propanoic acid. Is this a buffer solution, and if so, what is its pH?

A solution is prepared by adding 500 mL of 0.3 M NaClO to 500 mL of 0.4 M HClO. What is the pH of this solution?

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

What will be the effect of adding 0.5 mL of 0.1 M NaOH to 100 mL of an acetate buffer in which [CH3COOH] = [CH3COO¯] = 0.5 M?

The solubility of aluminum hydroxide in water ______________ when dilute nitric acid is added to it.

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 * 10¯4

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 Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

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 magnesium sulfate, MgSO₄, when placed into a 0.10 M MgCl₂ solution. K_sp = 5.9 *10¯³

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?

Citric acid has an acid dissociation constant of 8.4 *10¯⁴. It would be most effective for preparation of a buffer with a pH of:

What is the pH of a buffer that consists of 0.20 M NaH₂PO₄ and 0.40 M Na₂HPO₄? For NaH₂PO₄, K_a = 6.2*10¯⁸

The solubility of silver chromate is 0.0287 g/1.0 L of solution. What is the K_sp for Ag₂CrO₄?

Calculate the solubility of zinc hydroxide, Zn(OH)₂, in 1.00 M NaOH.

What is the [H₃O⁺] in a buffer that consists of 0.30 M HCOOH and 0.20 M HCOONa? For HCOOH, K_a = 1.7 * 10¯⁴

What volume of 0.500 M H₂SO₄ is needed to react completely with 20.0 mL of 0.400 M LiOH?

What will be the effect of adding 0.5 mL of 0.1 M NaOH to 100 mL of an acetate buffer in which [CH₃COOH] = [CH₃COO¯] = 0.5 M?

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 * 10¯⁴