Question 1

A solution is prepared by adding 0.10 mol of potassium chloride, KCl, to 1.00 L of water. Which statement about the solution is correct?

Accepted Answer

A)  The solution is basic. 
B)  The solution is neutral. 
C)  The solution is acidic. 
D)  One needs to know the temperature before any of the above predictions can be made. 
E)  The values for Ka and Kb for the species in solution must be known before a prediction can be made. 
A)  The solution is basic. 
B)  The solution is neutral. 
C)  The solution is acidic. 
D)  One needs to know the temperature before any of the above predictions can be made. 
E)  The values for Ka and Kb for the species in solution must be known before a prediction can be made.

Question 2

The chloride ion, Cl¯, is a typical Lewis acid.

Accepted Answer

A) True 
 B)False

Question 3

The substance HOBr is considered

Accepted Answer

A)  a weak Arrhenius acid. 
B)  a weak Arrhenius base. 
C)  a strong Arrhenius acid. 
D)  a strong Arrhenius base. 
E)  a neutral compound. 
A)  a weak Arrhenius acid. 
B)  a weak Arrhenius base. 
C)  a strong Arrhenius acid. 
D)  a strong Arrhenius base. 
E)  a neutral compound.

Question 4

Select the pair of substances which is not a conjugate acid-base pair.

Accepted Answer

A)  H3O+, H2O 
B)  HNO2, NO2¯ 
C)  H2SO4, HSO4¯ 
D)  H2S, S2¯ 
E)  NH3, NH2¯ 
A)  H3O+, H2O 
B)  HNO2, NO2¯ 
C)  H2SO4, HSO4¯ 
D)  H2S, S2¯ 
E)  NH3, NH2¯

Question 5

What is the value of Ka for the methylammonium ion, CH3NH3+? Kb(CH3NH2) = 4.4 *10¯4

Accepted Answer

A)  4.4 * 10¯4 
B)  4.8 * 10¯6 
C)  4.4 * 10¯10 
D)  2.3 * 10¯11 
E)  4.4 * 10¯18 
A)  4.4 * 10¯4 
B)  4.8 * 10¯6 
C)  4.4 * 10¯10 
D)  2.3 * 10¯11 
E)  4.4 * 10¯18

Question 6

Lactic acid has a pKa of 3.08. What is the approximate degree of dissociation of a 0.35 M solution of lactic acid?

Accepted Answer

A)  1.1% 
B)  2.2% 
C)  4.8% 
D)  14% 
E)  None of these choices is correct. 
A)  1.1% 
B)  2.2% 
C)  4.8% 
D)  14% 
E)  None of these choices is correct.

Question 7

An aqueous solution is prepared by dissolving the salt formed by the neutralization of a weak acid by a weak base. Which statement about the solution is correct?

Accepted Answer

A)  The solution is strongly basic. 
B)  The solution is weakly basic. 
C)  The solution is neutral. 
D)  The solution is acidic. 
E)  The values for Ka and Kb for the species in solution must be known before a prediction can be made. 
A)  The solution is strongly basic. 
B)  The solution is weakly basic. 
C)  The solution is neutral. 
D)  The solution is acidic. 
E)  The values for Ka and Kb for the species in solution must be known before a prediction can be made.

Question 8

Which of the following is the strongest base?

Accepted Answer

A)  CH3NH2 
B)  NaNO3 
C)  B(OH)3 
D)  Al(OH)3 
E)  LiOH 
A)  CH3NH2 
B)  NaNO3 
C)  B(OH)3 
D)  Al(OH)3 
E)  LiOH

Question 9

The ammonium ion, NH4+, is a weak acid.

Accepted Answer

A) True 
 B)False

Question 10

A 1.25 M solution of the weak acid HA is 9.2% dissociated. What is the pH of the solution?

Accepted Answer

A)  0.64 
B)  0.94 
C)  1.13 
D)  2.16 
E)  None of these choices is correct. 
A)  0.64 
B)  0.94 
C)  1.13 
D)  2.16 
E)  None of these choices is correct.

Question 11

What is the pH of a 0.050 M HBr solution?

Accepted Answer

A)  0.89 
B)  1.12 
C)  1.30 
D)  3.00 
E)  None of these choices is correct. 
A)  0.89 
B)  1.12 
C)  1.30 
D)  3.00 
E)  None of these choices is correct.

Question 12

Which one of the following is a strong acid?

Accepted Answer

A)  H2CO3 
B)  H2SO3 
C)  H2SO4 
D)  H3PO4 
E)  CH3COOH 
A)  H2CO3 
B)  H2SO3 
C)  H2SO4 
D)  H3PO4 
E)  CH3COOH

Question 13

What is the pH of a 0.20 M HCl solution?

Accepted Answer

A)  < 0 
B)  0.70 
C)  1.61 
D)  12.39 
E)  13.30 
A)  < 0 
B)  0.70 
C)  1.61 
D)  12.39 
E)  13.30

Question 14

All Lewis acids contain at least one proton.

Accepted Answer

A) True 
 B)False

Question 15

Which one of the following substances will give an aqueous solution of pH closest to 7?

Accepted Answer

A)  KNO3 
B)  CO2 
C)  NH4I 
D)  NH3 
E)  CH3NH2 
A)  KNO3 
B)  CO2 
C)  NH4I 
D)  NH3 
E)  CH3NH2

Question 16

In order to be a Brønsted-Lowry base, a species must contain a proton.

Accepted Answer

A) True 
 B)False

Question 17

Which of the following aqueous liquids is the most acidic?

Accepted Answer

A)  0.1 M Al(NO3)3, Ka = 1 *10¯5 
B)  0.1 M Be(NO3)2, Ka = 4 *10¯6 
C)  0.1 M Pb(NO3)2, Ka = 3 *10¯8 
D)  0.1 M Ni(NO3)2, Ka = 1 * 10¯10 
E)  pure water 
A)  0.1 M Al(NO3)3, Ka = 1 *10¯5 
B)  0.1 M Be(NO3)2, Ka = 4 *10¯6 
C)  0.1 M Pb(NO3)2, Ka = 3 *10¯8 
D)  0.1 M Ni(NO3)2, Ka = 1 * 10¯10 
E)  pure water

Question 18

The substance Ca(OH)2 is considered

Accepted Answer

A)  a weak Arrhenius acid. 
B)  a weak Arrhenius base. 
C)  a strong Arrhenius acid. 
D)  a strong Arrhenius base. 
E)  a neutral compound. 
A)  a weak Arrhenius acid. 
B)  a weak Arrhenius base. 
C)  a strong Arrhenius acid. 
D)  a strong Arrhenius base. 
E)  a neutral compound.

Question 19

Aqueous solutions of phosphoric acid and sodium nitrite are combined, and the following equilibrium is established.   The equilibrium constant Kc for this reaction is greater than one. Based on this information, which of the following statements is correct?

Accepted Answer

A)  Phosphoric acid is a weaker acid than nitrous acid. 
B)  Nitrous acid is a weaker acid than water. 
C)  The nitrite anion is a weaker base than the dihydrogen phosphate anion. 
D)  The dihydrogen phosphate anion is a stronger acid than nitrous acid. 
E)  Phosphoric acid is a stronger acid than nitrous acid. 
A)  Phosphoric acid is a weaker acid than nitrous acid. 
B)  Nitrous acid is a weaker acid than water. 
C)  The nitrite anion is a weaker base than the dihydrogen phosphate anion. 
D)  The dihydrogen phosphate anion is a stronger acid than nitrous acid. 
E)  Phosphoric acid is a stronger acid than nitrous acid.

Question 20

What is the value of Kb for the cyanide anion, CN¯? Ka(HCN) = 6.2 * 10¯10

Accepted Answer

A)  1.6 * 10¯4 
B)  1.6 * 10¯5 
C)  3.8 *10¯4 
D)  3.8 * 10¯5 
E)  6.2 * 104 
A)  1.6 * 10¯4 
B)  1.6 * 10¯5 
C)  3.8 *10¯4 
D)  3.8 * 10¯5 
E)  6.2 * 104

Exam 18: Acid-Base Equilibria

A solution is prepared by adding 0.10 mol of potassium chloride, KCl, to 1.00 L of water. Which statement about the solution is correct?

The chloride ion, Cl¯, is a typical Lewis acid.

The substance HOBr is considered

Select the pair of substances which is not a conjugate acid-base pair.

What is the value of Ka for the methylammonium ion, CH3NH3+? Kb(CH3NH2) = 4.4 *10¯4

Lactic acid has a pKa of 3.08. What is the approximate degree of dissociation of a 0.35 M solution of lactic acid?

An aqueous solution is prepared by dissolving the salt formed by the neutralization of a weak acid by a weak base. Which statement about the solution is correct?

Which of the following is the strongest base?

The ammonium ion, NH4+, is a weak acid.

A 1.25 M solution of the weak acid HA is 9.2% dissociated. What is the pH of the solution?

What is the pH of a 0.050 M HBr solution?

Which one of the following is a strong acid?

What is the pH of a 0.20 M HCl solution?

All Lewis acids contain at least one proton.

Which one of the following substances will give an aqueous solution of pH closest to 7?

In order to be a Brønsted-Lowry base, a species must contain a proton.

Which of the following aqueous liquids is the most acidic?

The substance Ca(OH)2 is considered

Aqueous solutions of phosphoric acid and sodium nitrite are combined, and the following equilibrium is established. The equilibrium constant Kc for this reaction is greater than one. Based on this information, which of the following statements is correct?

What is the value of Kb for the cyanide anion, CN¯? Ka(HCN) = 6.2 * 10¯10

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

Ionic Equilibria in Aqueous Systems

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

What is the value of K_a for the methylammonium ion, CH₃NH₃⁺? K_b(CH₃NH₂) = 4.4 *10¯⁴

Lactic acid has a pK_a of 3.08. What is the approximate degree of dissociation of a 0.35 M solution of lactic acid?

The ammonium ion, NH₄⁺, is a weak acid.

The substance Ca(OH)₂ is considered

Aqueous solutions of phosphoric acid and sodium nitrite are combined, and the following equilibrium is established. The equilibrium constant K_c for this reaction is greater than one. Based on this information, which of the following statements is correct?

What is the value of K_b for the cyanide anion, CN¯? K_a(HCN) = 6.2 * 10¯¹⁰