Question 1

Which of the following aqueous mixtures would be a buffer system?

Accepted Answer

A)  HCl, NaCl 
B)  HNO3, NaNO3 
C)  H3PO4, H2PO4- 
D)  H2SO4, CH3COOH 
E)  NH3, NaOH 
A)  HCl, NaCl 
B)  HNO3, NaNO3 
C)  H3PO4, H2PO4- 
D)  H2SO4, CH3COOH 
E)  NH3, NaOH

Question 2

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 3

The lab technician Anna Lytic adds 2.20 mol KOH to 1.00 L of 0.5 M Al(NO3)3. What is the concentration of aluminum ions after the aluminum nitrate has reacted with the potassium hydroxide? Kf = 3.0 × 1033 for Al(OH)4-

Accepted Answer

A)  1.8 × 10-7 M 
B)  9.1 × 10-18 M 
C)  1.0 × 10-31 M 
D)  3.3 × 10-34 M 
E)  7.1 × 10-36 M 
A)  1.8 × 10-7 M 
B)  9.1 × 10-18 M 
C)  1.0 × 10-31 M 
D)  3.3 × 10-34 M 
E)  7.1 × 10-36 M

Question 4

Write the ion product expression for calcium phosphate, Ca3(PO4)2.

Accepted Answer

A)    
B)    
C)    
D)    
E)  None of these choices are correct. 
A)    
B)    
C)    
D)    
E)  None of these choices are correct.

Question 5

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 6

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

Accepted Answer

A) True 
 B)False

Question 7

Calculate the solubility of strontium fluoride, SrF2, in pure water. Ksp = 2.6 × 10-9

Accepted Answer

A)  1.4 × 10-3 M 
B)  3.4 × 10-4 M 
C)  8.7 × 10-4 M 
D)  5.1 × 10-5 M 
E)  -5 M 
A)  1.4 × 10-3 M 
B)  3.4 × 10-4 M 
C)  8.7 × 10-4 M 
D)  5.1 × 10-5 M 
E)  -5 M

Question 8

What is the pH of a buffer that consists of 0.45 M CH3COOH and 0.35 M CH3COONa? Ka = 1.8 × 10-5

Accepted Answer

A)  4.49 
B)  4.64 
C)  4.85 
D)  5.00 
E)  5.52 
A)  4.49 
B)  4.64 
C)  4.85 
D)  5.00 
E)  5.52

Question 9

Calculate the solubility of silver chromate, Ag2CrO4, in 0.005 M Na2CrO4. Ksp = 2.6 × 10-12

Accepted Answer

A)  1.4 × 10-4 M 
B)  3.4 × 10-5 M 
C)  1.1 × 10-5 M 
D)  1.6 × 10-6 M 
E)  -6 M 
A)  1.4 × 10-4 M 
B)  3.4 × 10-5 M 
C)  1.1 × 10-5 M 
D)  1.6 × 10-6 M 
E)  -6 M

Question 10

For a diprotic acid H2A, the relationship Ka1 > Ka2 is always true.

Accepted Answer

A) True 
 B)False

Question 11

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 12

A lab technician adds 0.015 mol of KOH to 1.00 L of 0.0010 M Ca(NO3)2. Ksp = 6.5 × 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 13

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

Accepted Answer

A)  7.8 × 10-9 M 
B)  1.8 × 10-8 M 
C)  6.7 × 10-8 M 
D)  1.6 × 10-7 M 
E)  None of these choices are correct. 
A)  7.8 × 10-9 M 
B)  1.8 × 10-8 M 
C)  6.7 × 10-8 M 
D)  1.6 × 10-7 M 
E)  None of these choices are correct.

Question 14

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

Accepted Answer

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

Question 15

The solubility of magnesium phosphate is 2.27 × 10-3 g/1.0 L of solution. What is the Ksp for Mg3(PO4)2?

Accepted Answer

A)  6.5 × 10-12 
B)  6.0 × 10-14 
C)  5.2 × 10-24 
D)  4.8 × 10-26 
E)  1.0 × 10-26 
A)  6.5 × 10-12 
B)  6.0 × 10-14 
C)  5.2 × 10-24 
D)  4.8 × 10-26 
E)  1.0 × 10-26

Question 16

Which of the following indicators would be the best to use when 0.050 M benzoic acid (Ka = 6.6 × 10-5) is titrated with 0.05 M NaOH?

Accepted Answer

A)  bromphenol blue, pH range: 3.0-4.5 
B)  bromcresol green, pH range: 3.8-5.4 
C)  alizarin, pH range: 5.7-7.2 
D)  phenol red, pH range: 6.9-8.2 
E)  phenolphthalein, pH range: 8.0-10.1 
A)  bromphenol blue, pH range: 3.0-4.5 
B)  bromcresol green, pH range: 3.8-5.4 
C)  alizarin, pH range: 5.7-7.2 
D)  phenol red, pH range: 6.9-8.2 
E)  phenolphthalein, pH range: 8.0-10.1

Question 17

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 are 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 are correct.

Question 18

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 19

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. mL NaOH added 5.00 10.00 1.00 2.00
PH 6.98 7.46 7.93 10.31
What is the Ka for HClO?

Accepted Answer

A)  1.1 × 10-7 
B)  3.5 × 10-8 
C)  1.2 × 10-8 
D)  4.9 × 10-11 
E)  None of these choices are correct. 
A)  1.1 × 10-7 
B)  3.5 × 10-8 
C)  1.2 × 10-8 
D)  4.9 × 10-11 
E)  None of these choices are correct.

Question 20

Which of the following acids should be used to prepare a buffer with a pH of 4.5?

Accepted Answer

A)  HOC6H4OCOOH, Ka = 1.0 × 10-3 
B)  C6H4(COOH)2, Ka = 2.9 × 10-4 
C)  CH3COOH, Ka = 1.8 × 10-5 
D)  C5H5O5COOH, Ka = 4.0 × 10-6 
E)  HBrO, Ka = 2.3 × 10-9 
A)  HOC6H4OCOOH, Ka = 1.0 × 10-3 
B)  C6H4(COOH)2, Ka = 2.9 × 10-4 
C)  CH3COOH, Ka = 1.8 × 10-5 
D)  C5H5O5COOH, Ka = 4.0 × 10-6 
E)  HBrO, Ka = 2.3 × 10-9

Exam 19: Ionic Equilibria in Aqueous Systems

Which of the following aqueous mixtures would be a buffer system?

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

The lab technician Anna Lytic adds 2.20 mol KOH to 1.00 L of 0.5 M Al(NO3)3. What is the concentration of aluminum ions after the aluminum nitrate has reacted with the potassium hydroxide? Kf = 3.0 × 1033 for Al(OH)4-

Write the ion product expression for calcium phosphate, Ca3(PO4)2.

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?

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

Calculate the solubility of strontium fluoride, SrF2, in pure water. Ksp = 2.6 × 10-9

What is the pH of a buffer that consists of 0.45 M CH3COOH and 0.35 M CH3COONa? Ka = 1.8 × 10-5

Calculate the solubility of silver chromate, Ag2CrO4, in 0.005 M Na2CrO4. Ksp = 2.6 × 10-12

For a diprotic acid H2A, the relationship Ka1 > Ka2 is always true.

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

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

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

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

The solubility of magnesium phosphate is 2.27 × 10-3 g/1.0 L of solution. What is the Ksp for Mg3(PO4)2?

Which of the following indicators would be the best to use when 0.050 M benzoic acid (Ka = 6.6 × 10-5) is titrated with 0.05 M NaOH?

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

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. mL NaOH added 5.00 10.00 1.00 2.00 PH 6.98 7.46 7.93 10.31 What is the Ka for HClO?

Which of the following acids should be used to prepare a buffer with a pH of 4.5?

Keys to Studying Chemistry Definitions, Units, and Problem Solving

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 Reaction Direction

Electrochemistry Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

The lab technician Anna Lytic adds 2.20 mol KOH to 1.00 L of 0.5 M Al(NO₃)₃. What is the concentration of aluminum ions after the aluminum nitrate has reacted with the potassium hydroxide? K_f = 3.0 × 10³³ for Al(OH)₄^-

Write the ion product expression for calcium phosphate, Ca₃(PO₄)₂.

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?

Calculate the solubility of strontium fluoride, SrF₂, in pure water. K_sp = 2.6 × 10^-9

What is the pH of a buffer that consists of 0.45 M CH₃COOH and 0.35 M CH₃COONa? K_a = 1.8 × 10^-5

Calculate the solubility of silver chromate, Ag₂CrO₄, in 0.005 M Na₂CrO₄. K_sp = 2.6 × 10^-12

For a diprotic acid H₂A, the relationship K_a1 > K_a2 is always true.

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

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

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

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

The solubility of magnesium phosphate is 2.27 × 10^-3 g/1.0 L of solution. What is the K_sp for Mg₃(PO₄)₂?

Which of the following indicators would be the best to use when 0.050 M benzoic acid (K_a = 6.6 × 10^-5) is titrated with 0.05 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