Question 1

Which of the following is true of the equilibrium constants (K, Ka, Kb)?

Accepted Answer

A)  The smaller the value of Ka, the larger the value of Kb. 
B)  A small value of K indicates that ionization products are strongly favored. 
C)  A large value of K indicates that reactants are favored. 
D)  The strongest acids have the smallest Ka values. 
E)  The strongest bases have the smallest Kb values. 
A)  The smaller the value of Ka, the larger the value of Kb. 
B)  A small value of K indicates that ionization products are strongly favored. 
C)  A large value of K indicates that reactants are favored. 
D)  The strongest acids have the smallest Ka values. 
E)  The strongest bases have the smallest Kb values.

Question 2

Calculate the pH of the following aqueous solution: 0.17 M H2S (pKa1 = 7.00; pKa2 = 12.89)

Accepted Answer

A)  10.12 
B)  6.23 
C)  3.88 
D)  7.77 
E)  7.00 
A)  10.12 
B)  6.23 
C)  3.88 
D)  7.77 
E)  7.00

Question 3

What is the equilibrium concentration of H2C2O4 in a 0.170 M oxalic acid, H2C2O4, solution? For oxalic acid, Ka1 = 5.6 × 10-2 and Ka2 = 5.1 × 10-5.

Accepted Answer

A)  9.6 × 10-2 M 
B)  9.8 × 10-2 M 
C)  1.7 × 10-1 M 
D)  5.1 × 10-5 M 
E)  7.4 × 10-2 M 
A)  9.6 × 10-2 M 
B)  9.8 × 10-2 M 
C)  1.7 × 10-1 M 
D)  5.1 × 10-5 M 
E)  7.4 × 10-2 M

Question 4

What is the pH of a 0.42 M solution of sodium propionate, NaC3H5O2, at 25°C? (propionic acid, HC3H5O2, is monoprotic and has a Ka = 1.3 × 10-5 at 25°C.. Kw = 1.01 × 10-14 )

Accepted Answer

A)  6.06 
B)  4.75 
C)  11.10 
D)  7.94 
E)  9.25 
A)  6.06 
B)  4.75 
C)  11.10 
D)  7.94 
E)  9.25

Question 5

Which are the Brønsted-Lowry bases in the following equilibrium? 
CH3COO-(aq) + H2O(l) $\rightleftharpoons$ CH3COOH(aq) + OH-(aq)

Accepted Answer

A)  CH3COO- and OH- 
B)  H2O and OH- 
C)  H2O, CH3COOH, and OH- 
D)  CH3COO- and CH3COOH 
E)  H2O and CH3COOH 
A)  CH3COO- and OH- 
B)  H2O and OH- 
C)  H2O, CH3COOH, and OH- 
D)  CH3COO- and CH3COOH 
E)  H2O and CH3COOH

Question 6

Consider the reaction CO32-(aq) + H2O(l) $\rightleftharpoons$ HCO3-(aq) + OH-(aq). Kb for CO32- is 2.1 × 10-4 at 25°C. What is Ka for the HCO3- ion at 25°C?

Accepted Answer

A)  4.8 × 103 
B)  4.8 × 10-11 
C)  2.1 × 10-4 
D)  7.2 × 10-12 
E)  9.2 × 10-8 
A)  4.8 × 103 
B)  4.8 × 10-11 
C)  2.1 × 10-4 
D)  7.2 × 10-12 
E)  9.2 × 10-8

Question 7

Which of the following species is amphiprotic in aqueous solution?

Accepted Answer

A)  CHNH3+ 
B)  H3O+ 
C)  HF 
D)  OCl− 
E)  H2PO4- 
A)  CHNH3+ 
B)  H3O+ 
C)  HF 
D)  OCl− 
E)  H2PO4-

Question 8

Molecules or ions that can alternately behave as either a Brønsted-Lowry acid or base are called

Accepted Answer

A)  polyanions. 
B)  hydronium ions. 
C)  polyprotic acids or bases. 
D)  conjugate acids or bases. 
E)  amphiprotic. 
A)  polyanions. 
B)  hydronium ions. 
C)  polyprotic acids or bases. 
D)  conjugate acids or bases. 
E)  amphiprotic.

Question 9

In the reaction CaO(s) + CO2(g) → CaCO3(s),

Accepted Answer

A)  O2- acts as a Lewis base and CO2 acts as a Lewis acid. 
B)  O2- acts as a Lewis base and Ca2+ acts as a Lewis acid. 
C)  CaO is the Lewis acid and CaCO3 is its conjugate base. 
D)  CO2 is the Lewis acid and CaCO3 is its conjugate base. 
E)  Ca2+ acts as a Lewis acid and CO32- acts as a Lewis base. 
A)  O2- acts as a Lewis base and CO2 acts as a Lewis acid. 
B)  O2- acts as a Lewis base and Ca2+ acts as a Lewis acid. 
C)  CaO is the Lewis acid and CaCO3 is its conjugate base. 
D)  CO2 is the Lewis acid and CaCO3 is its conjugate base. 
E)  Ca2+ acts as a Lewis acid and CO32- acts as a Lewis base.

Question 10

Which of the following molecules or ions is the strongest acid?

Accepted Answer

A)  CH3CO2- 
B)  CH3CO2H 
C)  CFH2CO2H 
D)  CF2HCO2H 
E)  CF3CO2H 
A)  CH3CO2- 
B)  CH3CO2H 
C)  CFH2CO2H 
D)  CF2HCO2H 
E)  CF3CO2H

Question 11

Which of the following pairs of species is not a conjugate acid-base pair?

Accepted Answer

A)  HOCl and OCl- 
B)  HNO2 and NO2+ 
C)  O2- and OH- 
D)  HSO4- and SO42- 
E)  H2CO3 and HCO3- 
A)  HOCl and OCl- 
B)  HNO2 and NO2+ 
C)  O2- and OH- 
D)  HSO4- and SO42- 
E)  H2CO3 and HCO3-

Question 12

Which of the following is the correct hydroxide ion (OH-) concentration of an aqueous solution with a pH of 2.77? (Kw = 1.01 × 10-14)

Accepted Answer

A)  5.9 × 10-12 M 
B)  1.7 × 10-3 M 
C)  5.2 × 10-2 M 
D)  1.1 × 101 M 
E)  5.9 × 102 M 
A)  5.9 × 10-12 M 
B)  1.7 × 10-3 M 
C)  5.2 × 10-2 M 
D)  1.1 × 101 M 
E)  5.9 × 102 M

Question 13

What is the equilibrium pH of an initially 4.9 M solution of hypoiodous acid, HOI, at 25°C (Ka = $2.3 \times 10 ^ { - 11 }$ ; Kw = 1.01 × 10-14)?

Accepted Answer

A)  4.97 
B)  7.00 
C)  5.12 
D)  4.82 
E)  8.34 
A)  4.97 
B)  7.00 
C)  5.12 
D)  4.82 
E)  8.34

Question 14

What is the H3O+ concentration in 0.0072 M NaOH(aq) at 25 °C? (Kw = 1.01 × 10-14)

Accepted Answer

A)  1.4 × 10-12 M 
B)  7.2 × 10-3 M 
C)  1.0 × 10-14 M 
D)  1.0 × 10-7 M 
E)  7.2 × 10-17 M 
A)  1.4 × 10-12 M 
B)  7.2 × 10-3 M 
C)  1.0 × 10-14 M 
D)  1.0 × 10-7 M 
E)  7.2 × 10-17 M

Question 15

Write a net ionic equation for the neutralization reaction of hydrochloric acid and potassium hydroxide. Identify the spectator ion(s).

Accepted Answer

Net ionic equation:

Question 16

All of the following species behave as Lewis acids EXCEPT ____.

Accepted Answer

A)  BH3 
B)  Al3+ 
C)  SO2 
D)  Al(OH)3 
E)  NH3 
A)  BH3 
B)  Al3+ 
C)  SO2 
D)  Al(OH)3 
E)  NH3

Question 17

Given the following equilibrium constants, 
Ka (HSO4-) = 1.2 × 10-2
Kb (CH3CO2-) = 5.6 × 10-10
Kw = 1.00 × 10-14
determine the equilibrium constant for the reaction below at 25 °C.
HSO4-(aq) + CH3CO2-(aq) $\rightleftharpoons$ SO42-(aq) + CH3CO2H(aq)

Accepted Answer

A)  6.7 × 10-12 
B)  2.1 × 10-7 
C)  1.5 × 10-3 
D)  6.7 × 102 
E)  2.1 × 107 
A)  6.7 × 10-12 
B)  2.1 × 10-7 
C)  1.5 × 10-3 
D)  6.7 × 102 
E)  2.1 × 107

Exam 17: Principles of Chemical Reactivity: the Chemistry of Acids and Bases

Which of the following is true of the equilibrium constants (K, Ka, Kb)?

Calculate the pH of the following aqueous solution: 0.17 M H2S (pKa1 = 7.00; pKa2 = 12.89)

What is the equilibrium concentration of H2C2O4 in a 0.170 M oxalic acid, H2C2O4, solution? For oxalic acid, Ka1 = 5.6 × 10-2 and Ka2 = 5.1 × 10-5.

What is the pH of a 0.42 M solution of sodium propionate, NaC3H5O2, at 25°C? (propionic acid, HC3H5O2, is monoprotic and has a Ka = 1.3 × 10-5 at 25°C.. Kw = 1.01 × 10-14 )

Which are the Brønsted-Lowry bases in the following equilibrium? CH3COO-(aq) + H2O(l) ⇌\rightleftharpoons⇌ CH3COOH(aq) + OH-(aq)

Consider the reaction CO32-(aq) + H2O(l) ⇌\rightleftharpoons⇌ HCO3-(aq) + OH-(aq). Kb for CO32- is 2.1 × 10-4 at 25°C. What is Ka for the HCO3- ion at 25°C?

Which of the following species is amphiprotic in aqueous solution?

Molecules or ions that can alternately behave as either a Brønsted-Lowry acid or base are called

In the reaction CaO(s) + CO2(g) → CaCO3(s),

Which of the following molecules or ions is the strongest acid?

Which of the following pairs of species is not a conjugate acid-base pair?

Which of the following is the correct hydroxide ion (OH-) concentration of an aqueous solution with a pH of 2.77? (Kw = 1.01 × 10-14)

What is the equilibrium pH of an initially 4.9 M solution of hypoiodous acid, HOI, at 25°C (Ka = 2.3×10−112.3 \times 10 ^ { - 11 }2.3×10−11 ; Kw = 1.01 × 10-14)?

What is the H3O+ concentration in 0.0072 M NaOH(aq) at 25 °C? (Kw = 1.01 × 10-14)

Write a net ionic equation for the neutralization reaction of hydrochloric acid and potassium hydroxide. Identify the spectator ion(s).

All of the following species behave as Lewis acids EXCEPT ____.

Given the following equilibrium constants, Ka (HSO4-) = 1.2 × 10-2 Kb (CH3CO2-) = 5.6 × 10-10 Kw = 1.00 × 10-14 determine the equilibrium constant for the reaction below at 25 °C. HSO4-(aq) + CH3CO2-(aq) ⇌\rightleftharpoons⇌ SO42-(aq) + CH3CO2H(aq)

Basic Concepts of Chemistry

Lets Review: the Tools of Quantitative Chemistry

Atoms, Molecules, and Ions

Chemical Reactions

Stoichiometry: Quantitative Information About Chemical Reactions

Principles of Chemical Reactivity: Energy and Chemical Reactions

The Structure of Atoms

The Structure of Atoms and Periodic Trends

Bonding and Molecular Structure

Bonding and Molecular Structure Orbital Hybridization and Molecular Orbitals

Gases and Their Properties

Intermolecular Forces and Liquids

The Solid State

Solutions and Their Behavior

Chemical Kinetics: the Rates of Chemical Reactions

Principles of Chemical Reactivity: Equilibria

Principles of Chemical Reactivity: Other Aspects of Aqueous Equilibria

Principles of Chemical Reactivity: Entropy and Free Energy

Principles of Chemical Reactivity: Electron Transfer Reactions

Environmental Chemistry: Earths Environment, Energy, and Sustainability

The Chemistry of the Main Group Elements

The Chemistry of the Transition Elements

Carbon: Not Just Another Element

Biochemistry

Nuclear Chemistry

Filters

Calculate the pH of the following aqueous solution: 0.17 M H₂S (pK_a1 = 7.00; pK_a2 = 12.89)

What is the equilibrium concentration of H₂C₂O₄ in a 0.170 M oxalic acid, H₂C₂O₄, solution? For oxalic acid, K_a1 = 5.6 × 10^-2 and K_a2 = 5.1 × 10^-5.

What is the pH of a 0.42 M solution of sodium propionate, NaC₃H₅O₂, at 25°C? (propionic acid, HC₃H₅O₂, is monoprotic and has a K_a = 1.3 × 10^-5 at 25°C.. K_w = 1.01 × 10^-14 )

Which are the Brønsted-Lowry bases in the following equilibrium? CH₃COO^-(aq) + H₂O(l) $\rightleftharpoons$ CH₃COOH(aq) + OH^-(aq)

Consider the reaction CO₃^2-(aq) + H₂O(l) $\rightleftharpoons$ HCO₃^-(aq) + OH^-(aq). K_b for CO₃^2- is 2.1 × 10^-4 at 25°C. What is K_a for the HCO₃^- ion at 25°C?

In the reaction CaO(s) + CO₂(g) → CaCO₃(s),

Which of the following is the correct hydroxide ion (OH^-) concentration of an aqueous solution with a pH of 2.77? (K_w = 1.01 × 10^-14)

What is the equilibrium pH of an initially 4.9 M solution of hypoiodous acid, HOI, at 25°C (K_a = $2.3 \times 10 ^ { - 11 }$ ; K_w = 1.01 × 10^-14)?

What is the H₃O⁺ concentration in 0.0072 M NaOH(aq) at 25 °C? (K_w = 1.01 × 10^-14)

Given the following equilibrium constants, K_a (HSO₄^-) = 1.2 × 10^-2K_b (CH₃CO₂^-) = 5.6 × 10^-10 K_w = 1.00 × 10^-14determine the equilibrium constant for the reaction below at 25 °C. HSO₄^-(aq) + CH₃CO₂^-(aq) $\rightleftharpoons$ SO₄^2-(aq) + CH₃CO₂H(aq)