Electrochemistry Chapter 16 Exam Prep

Chapter 16: Electrochemistry

Test Bank

Type: multiple choice question

Title: Chapter 16 Question 01

1) What is the best description of the following reaction?

PbO₂ (s) + H₂O (l) + 2 e^– → PbO (s) + 2 OH^– (aq)

Section reference: 16.1

a. Oxidation of PbO₂

b. Hydrolysis of PbO₂

c. Reduction of PbO₂

d. disproportionation of PbO₂

Type: multiple choice question

Title: Chapter 16 Question 02

2) The position of equilibrium for the cell

Cr₂O₇^2– (aq) + 6 Fe²⁺(aq) + 14 H⁺(aq)  2 Cr³⁺ (aq) + 6 Fe³⁺ (aq) + 7 H₂O (l)

favours the formation of products. Identify the half-cell processes that occur at the anode and cathode.

Section reference: 16.3

a. Cathode: Cr₂O₇^2–/Cr³⁺ Anode: Fe³⁺/Fe²⁺

b. Cathode: Cr³⁺/Cr²⁺ Anode: Fe³⁺/Fe

c. Cathode: Fe³⁺/Fe Anode: Cr³⁺/Cr²⁺

d. Cathode: Fe³⁺/Fe²⁺ Anode: Cr₂O₇^2–/Cr³⁺ 

Type: multiple choice question

Title: Chapter 16 Question 03

3) Determine the limiting molar conductivity of an aqueous solution of magnesium chloride, MgCl₂ (aq).

Section reference: 16.2

a. 3.0 mS m² mol^–1

b. 18.2 mS m² mol^–1

c. 25.8 mS m² mol^–1

d. 28.8 mS m² mol^–1

Type: multiple choice question

Title: Chapter 16 Question 04

4) The conductivity of an aqueous solution of ammonium sulphate, (NH₄)₂SO₄ (aq) is 0.316 S m^–1. Calculate the concentration of the solution.

Section reference: 16.2

a. 0.0110 mol dm^–3

b. 0.0148 mol dm^–3

c. 0.0091 mol dm^–3

d. 0.0898 mol dm^–3

Type: multiple choice question

Title: Chapter 16 Question 05

5) The conductivity of a solution of ethanoic acid, CH₃COOH, is
5.05 × 10^–4 S m^–1. Calculate the pH of the solution.

Section reference: 16.2

a. 1.9

b. 4.9

c. 3.3

d. 11.3

Type: multiple choice question

Title: Chapter 16 Question 06

6) The conductivity of a solution of methanoic acid, HCOOH, which was made by dissolving 0.921 g of acid in water and making up the volume to 1.00 dm³, was measured to be 5.05 × 10^–4 S m^–1 at a temperature of 298 K. Determine the acid dissociation constant of methanoic acid at this temperature.

Section reference: 16.2

a. 0.234

b. 1.82

c. 0.550

d. 0.192

Type: multiple choice question

Title: Chapter 16 Question 07

7) Use the data for the standard reduction potentials given in Table 17.2 to predict which of the following is the strongest oxidising agent in acidic solution: OCl^– (aq), Cr₂O₇^– (aq), H₂O₂ (aq) or MnO₄^– (aq)

Section reference: 16.3

a. OCl^– (aq)

b. Cr₂O₇^– (aq)

c. H₂O₂ (aq)

d. MnO₄^– (aq)

Type: multiple choice question

Title: Chapter 16 Question 08

8) By considering the standard reduction potentials given in Table 7.2, decide which of the following metals could be used as a sacrificial coating to protect nickel metal, Ni (s).

Section reference: 16.3

a. Copper, Cu (s)

b. Magnesium, Mg (s)

c. Silver, Ag (s)

d. Tin, Sn (s)

Type: multiple choice question

Title: Chapter 16 Question 09

9) Calculate the standard cell potential for the reaction

2 MnO₄^–(aq) + 5 Sn²⁺ (aq) + 16 H⁺ (aq) →  2 Mn²⁺ (aq) + 5 Sn⁴⁺ (aq) + 8 H₂O

at a temperature of 298 K.

Section reference: 16.3

a. –1.57 V

b. +1.37 V

c. +3.14 V

d. +2.29 V

Type: multiple choice question

Title: Chapter 16 Question 10

10) Determine the standard cell potential at 298 K for the reaction

2 OH^– (aq) + Cl₂ (g) → Cl^– (aq) + OCl^– (aq) + H₂O (l)

using the data for the standard reduction potentials in Table 17.2.

Section reference: 16.3

a. +0.47 V

b. –0.94 V

c. +2.25 V

d. 0.00 V

Type: multiple choice question

Title: Chapter 16 Question 11

11) Determine the amount of electrical work that can be done by the system in the reaction

Cu (s) + Zn²⁺ (aq) → Cu²⁺ (aq) + Zn (s)

for which

Section reference: 16.4

a. –212 kJ mol^–1

b. –106 kJ mol^–1

c. –54 kJ mol^–1

d. –2.20 kJ mol^–1

Type: multiple choice question

Title: Chapter 16 Question 12

12) Determine the standard Gibbs energy change at 298 K for the reaction

Hg₂²⁺ (aq) + 2 Cl^– (aq) →  Hg₂Cl₂ (s)

using the data for the standard reduction potentials in Table 17.2.

Section reference: 16.4

a. –205 kJ mol^–1

b. –50 kJ mol^–1

c. +205 kJ mol^–1

d. –100 kJ mol^–1

Type: multiple choice question

Title: Chapter 16 Question 13

13) The standard Gibbs energy change for the reaction

H⁺ (aq) + OH^– (aq) → H₂O (l)

is –80.1 kJ mol^–1 at 298 K. Determine the standard reaction potential for the cell

Pt (s) | O₂ (g) | H⁺ (aq) ║ OH^– (aq) | O₂ (g) | Pt (s)

at this temperature.

Section reference: 16.4

a. +0.83 V

b. +3.32 V

c. +0.21 V

d. +0.19 V

Type: multiple choice question

Title: Chapter 16 Question 14

14) Using the standard reduction potentials in Table 17.2 to calculate the equilibrium constant for the reaction

Fe³⁺ (aq) + V²⁺ (aq) → Fe²⁺ (aq) + V³⁺ (aq)

at a temperature of 298 K.

Section reference: 16.3, 16.4

a. 1.3 × 10⁴⁰

b. 3.8 × 10^–18

c. 2.6 × 10¹⁷

d. 4.2 × 10⁸

Type: multiple choice question

Title: Chapter 16 Question 15

15) The standard cell potential for the reaction

6 [Fe(CN)₆]^3– (aq) + 2 Cr³⁺ (aq) + 7 H₂O (aq) → Cr₂O₇^2– (aq) + 14 H⁺ + 6 [Fe(CN)₆]^4– (aq)

has a value of –0.97 V at 298 K. Predict whether the reaction, as written, will be spontaneous in the forward direction at this temperature.

Section reference: 16.4

a. The reaction is spontaneous in the forward direction

b. The reaction is at equilibrium

c. The reaction is spontaneous in the backward direction

d. It is not possible to determine from the standard cell potential alone, whether the reaction will be spontaneous

Type: multiple choice question

Title: Chapter 16 Question 16

16) Use the Nernst equation to calculate the cell potential for the cell

Al (s) | Al³⁺ (aq, c = 0.20 mol dm^–3) ║ Cu²⁺ (aq, c = 0.10 mol dm^–3) | Cu (s)

at a temperature of 298 K.

Section reference: 16.4

a. +1.98 V

b. +2.02 V

c. +0.02 V

d. +2.00 V

Type: multiple choice question

Title: Chapter 16 Question 17

17) Determine the change in standard Gibbs energy at 298 K for the reaction

PbO₂ (s) + Pb (s) + 2 H₂SO₄ (aq) → 2 PbSO₄ (aq) + 2 H₂O (l)

which this basis of the lead–acid battery.

Section reference: 16.4, 16.5

a. –394 kJ mol^–1

b. –197 kJ mol^–1

c. –163 kJ mol^–1

d. –201 kJ mol^–1

Type: multiple choice question

Title: Chapter 16 Question 18

18) A concentration cell is formed by dipping two copper, Cu (s) electrodes into copper sulfate, CuSO₄ (aq), solutions of different concentrations, and joining the half cells by a salt bridge. Determine the ratio of the concentrations of the copper sulfate solutions necessary to create a potential difference between the electrodes of 0.10 V.

Section reference: 16.4

a. 2400

b. 10

c. 6.1 × 10⁷

d. 1300

Type: multiple choice question

Title: Chapter 16 Question 19

20) Use the standard reduction potentials for the Ag(s)/AgCl(s) and Ag⁺(aq)/Ag(s) half cells in Table 16.2 to determine the solubility product of silver chloride, AgCl, at 298 K.

Section reference: 16.4

a. 1.8 × 10¹⁷

b. 5.6 × 10^–10

c. 6.4 × 10⁹

d. 1.6 × 10^–10

Type: multiple choice question

Title: Chapter 16 Question 20

21) Determine the limiting molar conductivity of an aqueous solution of ammonium chloride, NH₄Cl (aq).

Section reference: 16.2

a. 15.0 mS m² mol^–1

b. 22.6 mS m² mol^–1

c. 147.6 mS m² mol^–1

d. 14.8  mS m² mol^–1

Type: multiple choice question

Title: Chapter 16 Question 21

22) The standard cell potential for the reaction

2Al (s) + 3Sn²⁺(aq) → 2Al³⁺(aq) + 3Sn (s)

has a value of +1.53 V at 298 K. Predict whether the reaction, as written, will be spontaneous in the forward direction at this temperature.

Section reference: 16.4

a. The reaction is spontaneous in the forward direction

b. The reaction is at equilibrium

c. The reaction is spontaneous in the backward direction

d. It is not possible to determine from the standard cell potential alone, whether the reaction will be spontaneous

Type: multiple choice question

Title: Chapter 16 Question 22

23) Determine the amount of electrical work that can be done by the system in the reaction

Ag⁺ (aq) + Fe²⁺ (aq) → Fe³⁺ (aq) + Ag (s)

using the data provided in Table 16.2.

Section reference: 16.4

a. –152 kJ mol^–1

b. –32 kJ mol^–1

c. –2.9 kJ mol^–1

d. –28.9 kJ mol^–1

Type: multiple choice question

Title: Chapter 16 Question 23

24) Determine the standard Gibbs energy change at 298 K for the reaction

2Ag⁺ (aq) + Zn(s) 🡪 2Ag(s) + Zn²⁺(aq)

using the data for the standard reduction potentials in Table 16.2.

Section reference: 16.4

a. –7.7 kJ mol^–1

b. –301 kJ mol^–1

c. +135 kJ mol^–1

d. –150 kJ mol^–1

Type: multiple choice question

Title: Chapter 16 Question 24

25) Calculate the standard cell potential for the reaction

3 Zn(s) + Cr₂O₇²⁻ (aq) + 14 H⁺ (aq) → 3 Zn²⁺ (aq) + 2Cr³⁺ (aq) + 7 H₂O (l)

at a temperature of 298 K.

Section reference: 16.3

a. –0.57 V

b. +1.37 V

c. +3.61 V

d. +2.09 V