Question 1

Which of the following aqueous solutions has the lowest [OH-]?

Accepted Answer

A) a solution with a pH of 3.0 
B) a 1 × 10-4 M solution of HNO3 
C) a solution with a pOH of 12.0 
D) pure water 
E) a 1 × 10-3 M solution of NH4Cl 
A) a solution with a pH of 3.0 
B) a 1 × 10-4 M solution of HNO3 
C) a solution with a pOH of 12.0 
D) pure water 
E) a 1 × 10-3 M solution of NH4Cl

Question 2

An aqueous solution at 25.0°C contains [H+] = 0.085 M. What is the pH of the solution?

Accepted Answer

A) 1.07 
B) -1.07 
C) 13.0 
D) 0.0850 
E) 1.20 ×   
A) 1.07 
B) -1.07 
C) 13.0 
D) 0.0850 
E) 1.20 ×

Question 3

An acid containing the COOH group is called a carbo-oxy acid.

Accepted Answer

A) True 
 B)False

Question 4

Which of the following ions will act as a weak base in water?

Accepted Answer

A) OH- 
B) Cl- 
C) NO3- 
D) ClO- 
E) None of the above will act as a weak base in water. 
A) OH- 
B) Cl- 
C) NO3- 
D) ClO- 
E) None of the above will act as a weak base in water.

Question 5

The magnitude of Kw indicates that ________.

Accepted Answer

A) water autoionizes very slowly 
B) water autoionizes very quickly 
C) water autoionizes only to a very small extent 
D) the autoionization of water is exothermic 
A) water autoionizes very slowly 
B) water autoionizes very quickly 
C) water autoionizes only to a very small extent 
D) the autoionization of water is exothermic

Question 6

Determine the pOH of a 0.10 M aqueous solution of KF. For hydrofluoric acid, Ka = 7.0 × 10-4.

Accepted Answer

A) 1.00 
B) 5.92 
C) 8.08 
D) 5.01 
E) 1.58 
A) 1.00 
B) 5.92 
C) 8.08 
D) 5.01 
E) 1.58

Question 7

The acid-dissociation constant at 25.0 °C for hypochlorous acid (HClO)is 3.0 × 10-8. At equilibrium, the molarity of H3O+ in a 0.066 M solution of HClO is ________.

Accepted Answer

A) 4.4 × 10-5 
B) 0.066 
C) 2.2 × 10-10 
D) 4.35 
E) 1.18 
A) 4.4 × 10-5 
B) 0.066 
C) 2.2 × 10-10 
D) 4.35 
E) 1.18

Question 8

Using the data in the table, which of the conjugate bases below is the weakest base?

Accepted Answer

A) OAc- 
B) CHO2- 
C) ClO- 
D) F- 
E) OAc- and CHO2- 
A) OAc- 
B) CHO2- 
C) ClO- 
D) F- 
E) OAc- and CHO2-

Question 9

A solution of acetic acid is 2.0% dissociated at 25.0°C. What was the original concentration (in M)of the acetic acid solution? The Ka at 25.0 °C for acetic acid is 1.8 × 10-5.

Accepted Answer

Question 10

A- is a weak base. Which equilibrium corresponds to the equilibrium constant Ka for HA?

Accepted Answer

A) HA (aq) + H2O (l)   H2A+ (aq) + OH- (aq) 
B) A- (aq) + H3O+ (aq)   HA (aq) + H2O (l) 
C) HA (aq) + H2O (l)   H3O+ (aq) + A- (aq) 
D) A- (aq) + H2O (l)   HA (aq) + OH- (aq) 
E) A- (aq) + OH- (aq)   HOA2- (aq) 
A) HA (aq) + H2O (l)   H2A+ (aq) + OH- (aq) 
B) A- (aq) + H3O+ (aq)   HA (aq) + H2O (l) 
C) HA (aq) + H2O (l)   H3O+ (aq) + A- (aq) 
D) A- (aq) + H2O (l)   HA (aq) + OH- (aq) 
E) A- (aq) + OH- (aq)   HOA2- (aq)

Question 11

A 1.0 × 10-2 M aqueous solution of Ca(OH)2 at 25.0 °C has a pH of ________.

Accepted Answer

A) 12.30 
B) 1.70 
C) 2.0 × 10-2 
D) 5.0 × 10-13 
E) 12.00 
A) 12.30 
B) 1.70 
C) 2.0 × 10-2 
D) 5.0 × 10-13 
E) 12.00

Question 12

In which of the following aqueous solutions does the weak acid exhibit the lowest percentage ionization?

Accepted Answer

A) 0.01 M HCN (Ka = 6.2 × 10-10) 
B) 0.01 M H2CO3 (Ka = 4.5 × 10-7) 
C) 0.01 M HNO2 (Ka = 4.0 × 10-4) 
D) 0.01 M HCHO2 (Ka = 1.8 × 10-4) 
E) 0.01 M HOCl (Ka = 3.5 × 10-8) 
A) 0.01 M HCN (Ka = 6.2 × 10-10) 
B) 0.01 M H2CO3 (Ka = 4.5 × 10-7) 
C) 0.01 M HNO2 (Ka = 4.0 × 10-4) 
D) 0.01 M HCHO2 (Ka = 1.8 × 10-4) 
E) 0.01 M HOCl (Ka = 3.5 × 10-8)

Question 13

The pH of a 0.30 M solution of a weak acid is 2.67. What is the Ka for this acid?

Accepted Answer

A) 2.1 × 10-4 
B) 4.4 × 10-4 
C) 1.5 × 10-4 
D) 6.6 × 10-4 
E) none of the above 
A) 2.1 × 10-4 
B) 4.4 × 10-4 
C) 1.5 × 10-4 
D) 6.6 × 10-4 
E) none of the above

Question 14

Calculate the concentration (in M)of hydronium ions in a solution at 25.0 °C with a pOH of 4.223.

Accepted Answer

A) 5.98 × 10-5 
B) 1.67 × 10-10 
C) 1.67 × 104 
D) 5.99 × 10-19 
E) 1.00 × 10-7 
A) 5.98 × 10-5 
B) 1.67 × 10-10 
C) 1.67 × 104 
D) 5.99 × 10-19 
E) 1.00 × 10-7

Question 15

Z- is a weak base. An aqueous solution of NaZ is prepared by dissolving 0.350 mol of NaZ in sufficient water to yield 1.0 L of solution. The pH of the solution was 8.93 at 25.0 °C. The Kb of Z- is ________.

Accepted Answer

A) 1.2 × 10-5 
B) 6.9 × 10-9 
C) 2.1 × 10-10 
D) 9.9 × 10-2 
E) 2.8 × 10-12 
A) 1.2 × 10-5 
B) 6.9 × 10-9 
C) 2.1 × 10-10 
D) 9.9 × 10-2 
E) 2.8 × 10-12

Question 16

Ka for HX is 7.5 × 10-12. What is the pH of a 0.15 M aqueous solution of NaX?

Accepted Answer

A) 7.97 
B) 1.96 
C) 6.00 
D) 8.04 
E) 12.10 
A) 7.97 
B) 1.96 
C) 6.00 
D) 8.04 
E) 12.10

Question 17

What is the concentration (in M)of hydroxide ions in a solution at 25.0 °C with pH = 4.282?

Accepted Answer

A) 4.28 
B) 9.72 
C) 1.92 × 10-10 
D) 5.22 × 10-5 
E) none of the above 
A) 4.28 
B) 9.72 
C) 1.92 × 10-10 
D) 5.22 × 10-5 
E) none of the above

Question 18

Which one of the following is the weakest acid?

Accepted Answer

A) HF (Ka = 6.8 × 10-4) 
B) HClO (Ka = 3.0 × 10-8) 
C) HNO2 (Ka = 4.5 × 10-4) 
D) HCN (Ka = 4.9 × 10-10) 
E) Acetic acid (Ka = 1.8 × 10-5) 
A) HF (Ka = 6.8 × 10-4) 
B) HClO (Ka = 3.0 × 10-8) 
C) HNO2 (Ka = 4.5 × 10-4) 
D) HCN (Ka = 4.9 × 10-10) 
E) Acetic acid (Ka = 1.8 × 10-5)

Question 19

Which solution will be the most basic?

Accepted Answer

A) 0.10 M Ba(OH)2 
B) 0.10 M KOH 
C) 0.10 M H2O 
D) 0.10 M CH3OH 
E) All solutions have equal basicity. 
A) 0.10 M Ba(OH)2 
B) 0.10 M KOH 
C) 0.10 M H2O 
D) 0.10 M CH3OH 
E) All solutions have equal basicity.

Question 20

Classify the following compounds as weak acids (W)or strong acids (S): hydrocyanic acid hydrofluoric acid phenol

Accepted Answer

A) W W W 
B) S S S 
C) S W W 
D) W S S 
E) W S W 
A) W W W 
B) S S S 
C) S W W 
D) W S S 
E) W S W

Exam 16: Acid-Base Equilibria

Which of the following aqueous solutions has the lowest [OH-]?

An aqueous solution at 25.0°C contains [H+] = 0.085 M. What is the pH of the solution?

An acid containing the COOH group is called a carbo-oxy acid.

Which of the following ions will act as a weak base in water?

The magnitude of Kw indicates that ________.

Determine the pOH of a 0.10 M aqueous solution of KF. For hydrofluoric acid, Ka = 7.0 × 10-4.

The acid-dissociation constant at 25.0 °C for hypochlorous acid (HClO)is 3.0 × 10-8. At equilibrium, the molarity of H3O+ in a 0.066 M solution of HClO is ________.

Using the data in the table, which of the conjugate bases below is the weakest base?

A solution of acetic acid is 2.0% dissociated at 25.0°C. What was the original concentration (in M)of the acetic acid solution? The Ka at 25.0 °C for acetic acid is 1.8 × 10-5.

A- is a weak base. Which equilibrium corresponds to the equilibrium constant Ka for HA?

A 1.0 × 10-2 M aqueous solution of Ca(OH)2 at 25.0 °C has a pH of ________.

In which of the following aqueous solutions does the weak acid exhibit the lowest percentage ionization?

The pH of a 0.30 M solution of a weak acid is 2.67. What is the Ka for this acid?

Calculate the concentration (in M)of hydronium ions in a solution at 25.0 °C with a pOH of 4.223.

Z- is a weak base. An aqueous solution of NaZ is prepared by dissolving 0.350 mol of NaZ in sufficient water to yield 1.0 L of solution. The pH of the solution was 8.93 at 25.0 °C. The Kb of Z- is ________.

Ka for HX is 7.5 × 10-12. What is the pH of a 0.15 M aqueous solution of NaX?

What is the concentration (in M)of hydroxide ions in a solution at 25.0 °C with pH = 4.282?

Which one of the following is the weakest acid?

Which solution will be the most basic?

Classify the following compounds as weak acids (W)or strong acids (S): hydrocyanic acid hydrofluoric acid phenol

Introduction: Matter and Measurement

Atoms, Molecules, and Ions

Stoichiometry: Calculations With Chemical Formulas and Equations

Aqueous Reactions and Solution Stoichiometry

Thermochemistry

Electronic Structure of Atoms

Periodic Properties of the Elements

Basic Concepts of Chemical Bonding

Molecular Geometry and Bonding Theories

Gases

Liquids and Intermolecular Forces

Solids and Modern Materials

Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Additional Aspects of Aqueous Equilibria

Chemistry of the Environment

Chemical Thermodynamics

Electrochemistry

Nuclear Chemistry

Chemistry of the Nonmetals

Transition Metals and Coordination Chemistry

The Chemistry of Life: Organic and Biological Chemistry

Filters

Which of the following aqueous solutions has the lowest [OH^-]?

An aqueous solution at 25.0°C contains [H⁺] = 0.085 M. What is the pH of the solution?

The magnitude of K_w indicates that ________.

Determine the pOH of a 0.10 M aqueous solution of KF. For hydrofluoric acid, K_a = 7.0 × 10^-4.

The acid-dissociation constant at 25.0 °C for hypochlorous acid (HClO)is 3.0 × 10^-⁸. At equilibrium, the molarity of H₃O⁺ in a 0.066 M solution of HClO is ________.

A solution of acetic acid is 2.0% dissociated at 25.0°C. What was the original concentration (in M)of the acetic acid solution? The K_a at 25.0 °C for acetic acid is 1.8 × 10^-5.

A- is a weak base. Which equilibrium corresponds to the equilibrium constant K_a for HA?

A 1.0 × 10^-2 M aqueous solution of Ca(OH)₂ at 25.0 °C has a pH of ________.

The pH of a 0.30 M solution of a weak acid is 2.67. What is the K_a for this acid?

Z^- is a weak base. An aqueous solution of NaZ is prepared by dissolving 0.350 mol of NaZ in sufficient water to yield 1.0 L of solution. The pH of the solution was 8.93 at 25.0 °C. The K_b of Z^-is ________.

K_a for HX is 7.5 × 10^-12. What is the pH of a 0.15 M aqueous solution of NaX?