Question 1

Determine the pH of a solution made by adding 1.0 × 10-7 mol of HCl to 1.0 L of solution.

Accepted Answer

Question 2

For nitrous acid, HNO2, Ka = 4.0 × 10-4. Calculate the pH of 0.33 M HNO2.

Accepted Answer

A)  2.92 
B)  1.94 
C)  3.40 
D)  0.48 
E)  4.36 
A)  2.92 
B)  1.94 
C)  3.40 
D)  0.48 
E)  4.36

Question 3

Calculate the pH of a 5.0 M solution of aniline (C6H5NH2; Kb = 3.8 × 10-10).

Accepted Answer

A)  9.64 
B)  9.30 
C)  4.36 
D)  -0.070 
E)  none of these 
A)  9.64 
B)  9.30 
C)  4.36 
D)  -0.070 
E)  none of these

Question 4

The conjugate acid and conjugate base of bicarbonate ion, HCO3-, are, respectively,

Accepted Answer

A)  H3O+ and OH- 
B)  H2CO3 and OH- 
C)  H3O+ and CO32- 
D)  H2CO3 and CO32- 
E)  CO32- and OH- 
A)  H3O+ and OH- 
B)  H2CO3 and OH- 
C)  H3O+ and CO32- 
D)  H2CO3 and CO32- 
E)  CO32- and OH-

Question 5

Calculate [H+] in a solution that has a pH of 9.4.

Accepted Answer

A)  1 × 10-1 M 
B)  3 × 10-5 M 
C)  9 M 
D)  5 M 
E)  4 × 10-10 M 
A)  1 × 10-1 M 
B)  3 × 10-5 M 
C)  9 M 
D)  5 M 
E)  4 × 10-10 M

Question 6

Calculate the pH of a solution that is 7.22 × 10-4 M C6H5NH2. Kb is 3.8 × 10-10.

Accepted Answer

A)  6.28 
B)  7.72 
C)  6.50 
D)  7.50 
E)  none of these 
A)  6.28 
B)  7.72 
C)  6.50 
D)  7.50 
E)  none of these

Question 7

The sodium salt, NaA, of a weak acid is dissolved in water; no other substance is added. Which of these statements (to a close approximation) is true?

Accepted Answer

A)  [H+] = [A-] 
B)  [A-] = [OH-] 
C)  [HA] = [OH-] 
D)  [H+] = [OH-] 
E)  none of these 
A)  [H+] = [A-] 
B)  [A-] = [OH-] 
C)  [HA] = [OH-] 
D)  [H+] = [OH-] 
E)  none of these

Question 8

Which of the following does not represent a conjugate acid-base pair?

Accepted Answer

A)  H3O+ and H2O 
B)  HCN and NH3 
C)  HF and F- 
D)  C5H5NH+ and C5H5N 
E)  none of these 
A)  H3O+ and H2O 
B)  HCN and NH3 
C)  HF and F- 
D)  C5H5NH+ and C5H5N 
E)  none of these

Question 9

Solid calcium hydroxide is dissolved in water until the pH of the solution is 10.94. What is the hydroxide ion concentration [OH-] of the solution?

Accepted Answer

A)  3.06 M 
B)  1.1 ×10-11 M 
C)  1.0 ×10-14 M 
D)  8.7 ×10-4 M 
E)  none of these 
A)  3.06 M 
B)  1.1 ×10-11 M 
C)  1.0 ×10-14 M 
D)  8.7 ×10-4 M 
E)  none of these

Question 10

If the following substance is dissolved in pure water, will the solution be acidic, neutral, or basic? solid ammonium nitrate (NH4NO3)

Accepted Answer

A)  basic 
B)  neutral 
C)  acidic 
A)  basic 
B)  neutral 
C)  acidic

Question 11

The pKa of HOCl is 7.5. Calculate the pH of a 0.5 M solution of HOCl.

Accepted Answer

A)  0.3 
B)  6.5 
C)  7.5 
D)  10.1 
E)  3.9 
A)  0.3 
B)  6.5 
C)  7.5 
D)  10.1 
E)  3.9

Question 12

A 2.5 M solution of a weak acid is 0.52% ionized. What is Ka for this acid?

Accepted Answer

A)  1.3 × 10-2 
B)  6.8 × 10-5 
C)  0.11 
D)  1.1 × 10-5 
E)  none of these 
A)  1.3 × 10-2 
B)  6.8 × 10-5 
C)  0.11 
D)  1.1 × 10-5 
E)  none of these

Question 13

Calculate the pH of a 0.048 M solution of KOH.

Accepted Answer

A)  12.68 
B)  11.32 
C)  1.32 
D)  2.68 
E)  none of these 
A)  12.68 
B)  11.32 
C)  1.32 
D)  2.68 
E)  none of these

Question 14

The pH of a solution is raised from 3 to 5. Which statement is false?

Accepted Answer

A)  The final [OH-] (at pH = 5) is 10-9 M. 
B)  The [H+] decreases by a factor of 20. 
C)  The initial solution could be 0.001 M HNO3. 
D)  The pOH decreases from 11 to 9. 
E)  The initial [H+] (at pH = 3) is 10-3 M. 
A)  The final [OH-] (at pH = 5) is 10-9 M. 
B)  The [H+] decreases by a factor of 20. 
C)  The initial solution could be 0.001 M HNO3. 
D)  The pOH decreases from 11 to 9. 
E)  The initial [H+] (at pH = 3) is 10-3 M.

Question 15

According to the Brønsted-Lowry definition, an acid is

Accepted Answer

A)  a substance that can donate a proton to another species. 
B)  a substance that increases the hydroxide ion concentration in a solution. 
C)  a substance that can accept a proton from another species in solution. 
D)  an electron pair acceptor. 
E)  a substance that increases the hydrogen ion concentration in a solution. 
A)  a substance that can donate a proton to another species. 
B)  a substance that increases the hydroxide ion concentration in a solution. 
C)  a substance that can accept a proton from another species in solution. 
D)  an electron pair acceptor. 
E)  a substance that increases the hydrogen ion concentration in a solution.

Question 16

Calculate the pH of a 0.05 M solution of ascorbic acid (Ka1 = 7.9 × 10-5; Ka2 = 1.6 × 10-12).

Accepted Answer

A)  5.4 
B)  3.1 
C)  6.5 
D)  1.3 
E)  2.7 
A)  5.4 
B)  3.1 
C)  6.5 
D)  1.3 
E)  2.7

Question 17

Calculate the pH of a 1.5 × 10-7 M solution of HCl.

Accepted Answer

A)  7.18 
B)  7.00 
C)  7.30 
D)  6.82 
E)  6.70 
A)  7.18 
B)  7.00 
C)  7.30 
D)  6.82 
E)  6.70

Question 18

Calculate [H+] in a 0.40 M solution of NaH2PO4. (For H3PO4, Ka1 = 7.5 × 10-3, Ka2 = 6.2 × 10-8, Ka3 = 4.8 × 10-13)

Accepted Answer

A)  1.6 × 10-4 M 
B)  2.5 × 10-4 M 
C)  0.40 M 
D)  3.9 × 10-11 M 
E)  2.2 × 10-5 M 
A)  1.6 × 10-4 M 
B)  2.5 × 10-4 M 
C)  0.40 M 
D)  3.9 × 10-11 M 
E)  2.2 × 10-5 M

Question 19

​What is the [H3O+] of a 0.14 M solution of NH4Cl in H2O at 25°C? (Kb for NH3 = 1.8 × 10-5)

Accepted Answer

A)  ​1.1 × 10-9 M 
B)  ​​8.8-6 M 
C)  2.5-6 M 
D)  7.8-9 M 
E)  ​​1.6-3 M 
A)  ​1.1 × 10-9 M 
B)  ​​8.8-6 M 
C)  2.5-6 M 
D)  7.8-9 M 
E)  ​​1.6-3 M

Question 20

In deciding which of two acids is the stronger, one must know

Accepted Answer

A)  the pH of each acid solution only. 
B)  the concentration of each acid solution only. 
C)  the equilibrium constant of each acid only. 
D)  all of the these. 
E)  both the concentration and the equilibrium constant of each acid. 
A)  the pH of each acid solution only. 
B)  the concentration of each acid solution only. 
C)  the equilibrium constant of each acid only. 
D)  all of the these. 
E)  both the concentration and the equilibrium constant of each acid.

Determine the pH of a solution made by adding 1.0 × 10^-7 mol of HCl to 1.0 L of solution.

For nitrous acid, HNO₂, K_a = 4.0 × 10^-4. Calculate the pH of 0.33 M HNO₂.

Calculate the pH of a 5.0 M solution of aniline (C₆H₅NH₂; K_b = 3.8 × 10^-10).

The conjugate acid and conjugate base of bicarbonate ion, HCO₃^-, are, respectively,

Calculate [H⁺] in a solution that has a pH of 9.4.

Calculate the pH of a solution that is 7.22 × 10^-4 M C₆H₅NH₂. K_b is 3.8 × 10^-10.

The sodium salt, NaA, of a weak acid is dissolved in water; no other substance is added. Which of these statements (to a close approximation) is true?

Which of the following does not represent a conjugate acid-base pair?

Solid calcium hydroxide is dissolved in water until the pH of the solution is 10.94. What is the hydroxide ion concentration [OH^-] of the solution?

If the following substance is dissolved in pure water, will the solution be acidic, neutral, or basic? solid ammonium nitrate (NH₄NO₃)

The pK_a of HOCl is 7.5. Calculate the pH of a 0.5 M solution of HOCl.

A 2.5 M solution of a weak acid is 0.52% ionized. What is K_a for this acid?

Calculate the pH of a 0.048 M solution of KOH.

The pH of a solution is raised from 3 to 5. Which statement is false?

According to the Brønsted-Lowry definition, an acid is

Calculate the pH of a 0.05 M solution of ascorbic acid (K_a1 = 7.9 × 10^-5; K_a2 = 1.6 × 10^-12).

Calculate the pH of a 1.5 × 10^-7 M solution of HCl.

Calculate [H⁺] in a 0.40 M solution of NaH₂PO₄. (For H₃PO₄, K_a1 = 7.5 × 10^-3, K_a2 = 6.2 × 10^-8, K_a3 = 4.8 × 10^-13)

What is the [H₃O⁺] of a 0.14 M solution of NH₄Cl in H₂O at 25°C? (K_b for NH₃ = 1.8 × 10^-⁵)

In deciding which of two acids is the stronger, one must know

Atoms, Molecules, and Ions

Stoichiometry

Types of Chemical Reactions and Solution Stoichiometry

Gases

Chemical Equilibrium

Applications of Aqueous Equilibria

Energy, Enthalpy, and Thermochemistry

Spontaneity, Entropy, and Free Energy

Electrochemistry

Quantum Mechanics and Atomic Theory

Bonding: General Concepts

Covalent Bonding: Orbitals

Chemical Kinetics

Liquids and Solids

Properties of Solutions

The Representative Elements

Transition Metals and Coordination Chemistry

The Nucleus: a Chemists View

Organic and Biochemical Molecules

Filters

Exam 7: Acids and Bases

Determine the pH of a solution made by adding 1.0 × 10-7 mol of HCl to 1.0 L of solution.

For nitrous acid, HNO2, Ka = 4.0 × 10-4. Calculate the pH of 0.33 M HNO2.

Calculate the pH of a 5.0 M solution of aniline (C6H5NH2; Kb = 3.8 × 10-10).

The conjugate acid and conjugate base of bicarbonate ion, HCO3-, are, respectively,

Calculate [H+] in a solution that has a pH of 9.4.

Calculate the pH of a solution that is 7.22 × 10-4 M C6H5NH2. Kb is 3.8 × 10-10.

The sodium salt, NaA, of a weak acid is dissolved in water; no other substance is added. Which of these statements (to a close approximation) is true?

Which of the following does not represent a conjugate acid-base pair?

Solid calcium hydroxide is dissolved in water until the pH of the solution is 10.94. What is the hydroxide ion concentration [OH-] of the solution?

If the following substance is dissolved in pure water, will the solution be acidic, neutral, or basic? solid ammonium nitrate (NH4NO3)

The pKa of HOCl is 7.5. Calculate the pH of a 0.5 M solution of HOCl.

A 2.5 M solution of a weak acid is 0.52% ionized. What is Ka for this acid?

Calculate the pH of a 0.048 M solution of KOH.

The pH of a solution is raised from 3 to 5. Which statement is false?

According to the Brønsted-Lowry definition, an acid is

Calculate the pH of a 0.05 M solution of ascorbic acid (Ka1 = 7.9 × 10-5; Ka2 = 1.6 × 10-12).

Calculate the pH of a 1.5 × 10-7 M solution of HCl.

Calculate [H+] in a 0.40 M solution of NaH2PO4. (For H3PO4, Ka1 = 7.5 × 10-3, Ka2 = 6.2 × 10-8, Ka3 = 4.8 × 10-13)

​What is the [H3O+] of a 0.14 M solution of NH4Cl in H2O at 25°C? (Kb for NH3 = 1.8 × 10-5)

In deciding which of two acids is the stronger, one must know

Atoms, Molecules, and Ions

Stoichiometry

Types of Chemical Reactions and Solution Stoichiometry

Gases

Chemical Equilibrium

Applications of Aqueous Equilibria

Energy, Enthalpy, and Thermochemistry

Spontaneity, Entropy, and Free Energy

Electrochemistry

Quantum Mechanics and Atomic Theory

Bonding: General Concepts

Covalent Bonding: Orbitals

Chemical Kinetics

Liquids and Solids

Properties of Solutions

The Representative Elements

Transition Metals and Coordination Chemistry

The Nucleus: a Chemists View

Organic and Biochemical Molecules

Filters

Determine the pH of a solution made by adding 1.0 × 10^-7 mol of HCl to 1.0 L of solution.

For nitrous acid, HNO₂, K_a = 4.0 × 10^-4. Calculate the pH of 0.33 M HNO₂.

Calculate the pH of a 5.0 M solution of aniline (C₆H₅NH₂; K_b = 3.8 × 10^-10).

The conjugate acid and conjugate base of bicarbonate ion, HCO₃^-, are, respectively,

Calculate [H⁺] in a solution that has a pH of 9.4.

Calculate the pH of a solution that is 7.22 × 10^-4 M C₆H₅NH₂. K_b is 3.8 × 10^-10.

Solid calcium hydroxide is dissolved in water until the pH of the solution is 10.94. What is the hydroxide ion concentration [OH^-] of the solution?

If the following substance is dissolved in pure water, will the solution be acidic, neutral, or basic? solid ammonium nitrate (NH₄NO₃)

The pK_a of HOCl is 7.5. Calculate the pH of a 0.5 M solution of HOCl.

A 2.5 M solution of a weak acid is 0.52% ionized. What is K_a for this acid?

Calculate the pH of a 0.05 M solution of ascorbic acid (K_a1 = 7.9 × 10^-5; K_a2 = 1.6 × 10^-12).

Calculate the pH of a 1.5 × 10^-7 M solution of HCl.

Calculate [H⁺] in a 0.40 M solution of NaH₂PO₄. (For H₃PO₄, K_a1 = 7.5 × 10^-3, K_a2 = 6.2 × 10^-8, K_a3 = 4.8 × 10^-13)

What is the [H₃O⁺] of a 0.14 M solution of NH₄Cl in H₂O at 25°C? (K_b for NH₃ = 1.8 × 10^-⁵)