Question 1

Determine E°cell for the reaction: Cl2 + 2 F- → 2 Cl- + F2. The half reactions are: F2(s) + 2 e- → 2 F-(aq)  &emsp;  E° = +2.866 V
Cl2(s) + 2 e- → 2 Cl-(aq) &emsp;  E° = 1.358 V

Accepted Answer

A)  3.016 V 
B)  -4.224 V 
C)  1.508 V 
D)  4.224 V 
E)  -1.508 V

Question 2

For the reaction: Mg(s) + AgNO3(aq) → Ag(s) + Mg(NO3)2(aq) Ag+(aq) + e- → Ag(s) E° = 0.800 V
Mg2+(aq) + 2 e- → Mg(s) E° = -2.356 V
For the reaction, determine E° for the cell.

Accepted Answer

A)  1.556 V 
B)  -3.156 V 
C)  3.156 V 
D)  0.800 V 
E)  2.356 V

Question 3

For the reaction: Mg(s) + AgNO3(aq) → Ag(s) + Mg(NO3)2(aq) Ag+(aq) + e- → Ag(s) E° = 0.800 V
Mg2+(aq) + 2 e- → Mg(s) E° = -2.356 V
Estimate Keq at 25°C.

Accepted Answer

A)  5.7 × 10106 
B)  2.0 × 1053 
C)  3.7 × 1052 
D)  1.1 × 1027 
E)  10-107

Question 4

Determine E°cell for the reaction: 2 Ag+ + Mg → 2 Ag + Mg2+. The half reactions are: Mg2+(aq) + 2 e- → Mg(s) E° = -2.356 V
Ag+(aq) + e- → Ag(s) E° = 0.800 V

Accepted Answer

A)  0.756 V 
B)  -0.756 V 
C)  3.156 V 
D)  -1.556 V 
E)  1.556 V

Question 5

What is the cell potential for the following cell at 25°C? Zn ∣ Zn2+ (0.0456 M) || Cu2+(0.120 M) ∣ Cu
Cu2+ + 2 e- → Cu(s)  &emsp; E° = 0.340 V
Zn2+ + 2 e- → Zn(s)  &emsp;  E° = -0.763 V

Accepted Answer

A)  1.088 V 
B)  1.114 V 
C)  1.106 V 
D)  1.094 V 
E)  1.129 V

Question 6

Accepted Answer

A)  I) and V) 
B)  II) and IV) 
C)  I) and IV) 
D)  II) and III) 
E)  I) and III)

Question 7

What is the cell potential for the following cell at 25°C? Al ∣ Al3+(0.00212 M) || Sn2+(0.435 M) ∣ Sn
Al3+ + 3 e- → Al(s)   &emsp; E° = -1.676 V
Sn2+ + 2 e- → Sn(s   &emsp; E° = -0.137 V

Accepted Answer

A)  1.517 V 
B)  1.668 V 
C)  1.410 V 
D)  1.497 V 
E)  1.581 V

Question 8

In a zinc-lead cell the reaction is: Pb2+ + Zn → Pb + Zn2+   &emsp;   &emsp; E° = 0.637 V
Which of the following statements about this cell is FALSE?

Accepted Answer

A)  The zinc electrode is the cathode. 
B)  The reaction will go in the direction indicated. 
C)  The shorthand notation is Zn ∣ Zn2+ = Pb2+ ∣ Pb 
D)  The actual cell voltage is less than +0.637 volts because of concentration polarization and possible other factors. 
E)  The lead electrode is positively charged.

Question 9

What is E° of the spontaneous cell made from the Zn2+/Zn (-0.76 V) and Br2/2Br- (1.07 V) half cells?

Accepted Answer

A)  -1.83 V 
B)  0.31 V 
C)  1.83 V 
D)  -0.31 V 
E)  -0.76 V

Question 10

Corrosion of metals is an oxidation-reduction process.

Accepted Answer

A) True 
 B)False

Question 11

For the following voltaic cell, determine the [Cl-] when PCl2 = 0.500 atm, [Zn2+] = 1.77 × 10-2 M, and Ecell = 2.250 V. The half-reactions at 25°C are: Cl2(g) + 2 e- → 2 Cl-(aq)  &emsp;  E° = +1.358 V
Zn2+(aq) + 2 e- → Zn(s)  &emsp;  E° = -0.763 V
Zn(s) ∣ Zn2+(aq) || Cl-(aq), Cl2(g) ∣ Pt(s)

Accepted Answer

A)  5.48 × 10-6 M 
B)  2.32 × 10-3 M 
C)  0.0296 M 
D)  0.0939 M 
E)  0.0352 M

Question 12

Determine E°cell for the reaction: Pb + Zn2+ → Pb2+ + Zn. The half reactions are: Pb2+(aq) + 2 e- → Pb(s)  &emsp;  E° = -0.125 V
Zn2+(aq) + 2 e- → Zn(s)   &emsp; E° = -0.763 V

Accepted Answer

A)  0.638 V 
B)  -0.638 V 
C)  0.888 V 
D)  -1.276 V 
E)  -0.888 V

Question 13

For the reaction: Mg(s) + AgNO3(aq) → Ag(s) + Mg(NO3)2(aq) Ag+(aq) + e- → Ag(s) E° = 0.800 V
Mg2+(aq) + 2 e- → Mg(s) E° = -2.356 V
Determine ΔG°.

Accepted Answer

A)  -300.3 kJ/mol 
B)  304.5 kJ/mol 
C)  609.0 kJ/mol 
D)  -304.5 kJ/mol 
E)  -609.0 kJ/mol

Question 14

The Ecell for the following concentration cell at 25°C is 0.006.
Pt ∣ H2 (g, 0.025 atm) ∣ H+ (0.012 M) = H+ (1 M) ∣ H2 (g, 1 atm) ∣ Pt
2 H+(aq) + 2 e- → H2(g) E° = 0. V

Accepted Answer

A) True 
 B)False

Question 15

Consider the following reaction: 2 Al + 3 Ni2+ → 2 Al3+ + 3 Ni E° = 1.410 v
What would be the cell potential at 25°C as calculated from the Nernst equation if [Ni2+] = 0.020 M, [Al3+] = 3.60 M?

Accepted Answer

A)  1.388 volts 
B)  1.034 volts 
C)  1.471 volts 
D)  1.349 volts 
E)  1.410 volts

Question 16

Determine the Ksp at 25°C of AgCl(s). The half-reactions are: Ag+(aq) + 1 e- → Ag(s) E° = +0.771 V
AgCl(s) + 1 e- → Ag(s) + Cl- E° = +0.222 V

Accepted Answer

A)  1 × 10-2 
B)  0.771 
C)  4 × 1011 
D)  5 × 10-10 
E)  4 × 10-11

Question 17

What is Keq at 25°C of the spontaneous cell made from the Zn2+/Zn (-0.76 V) and Br2/2Br- (1.07 V) half cells?

Accepted Answer

A)  10-6 
B)  105 
C)  1010 
D)  10-11 
E)  1061

Question 18

What is the Ecell for the following cell at 25°C? Pt ∣ Fe2+ (0.0562 M), Fe3+ (0.253 M) || Ag+ (0.334 M) ∣ Ag
Ag+ + e- → Ag(s)&emsp; &emsp;  E° = 0.800 V
Fe3+ + e- → Fe2+ &emsp; &emsp; E° = -0.771 V

Accepted Answer

A)  -0.038 V 
B)  1.500 V 
C)  -0.004 V 
D)  0.096 V 
E)  0.039 V

Question 19

In a galvanic cell, oxidation occurs at the:

Accepted Answer

A)  anode 
B)  cathode 
C)  salt bridge 
D)  electrolyte 
E)  in cathodic space

Question 20

Cathodic protection is attaching a more active metal to the protected metal.

Accepted Answer

A) True 
 B)False

Exam 20: Electrochemistry

Determine E°cell for the reaction: Cl₂ + 2 F- → 2 Cl- + F₂. The half reactions are: F₂(s) + 2 e- → 2 F-(aq) E° = +2.866 V Cl₂(s) + 2 e- → 2 Cl-(aq) E° = 1.358 V

For the reaction: Mg(s) + AgNO₃(aq) → Ag(s) + Mg(NO₃) ₂(aq) Ag⁺(aq) + e- → Ag(s) E° = 0.800 V Mg²⁺(aq) + 2 e- → Mg(s) E° = -2.356 V For the reaction, determine E° for the cell.

For the reaction: Mg(s) + AgNO₃(aq) → Ag(s) + Mg(NO₃) ₂(aq) Ag⁺(aq) + e- → Ag(s) E° = 0.800 V Mg₂+(aq) + 2 e- → Mg(s) E° = -2.356 V Estimate Keq at 25°C.

Determine E°cell for the reaction: 2 Ag+ + Mg → 2 Ag + Mg2+. The half reactions are: Mg2+(aq) + 2 e- → Mg(s) E° = -2.356 V Ag+(aq) + e- → Ag(s) E° = 0.800 V

What is the cell potential for the following cell at 25°C? Zn ∣ Zn²⁺ (0.0456 M) || Cu²⁺(0.120 M) ∣ Cu Cu²⁺ + 2 e- → Cu(s) E° = 0.340 V Zn²⁺ + 2 e- → Zn(s) E° = -0.763 V

Which of the following are commonly used as alternate standard electrodes: I. Ag(s) | AgCl(s) | Cl- (1.0 M) II. Hg(l) | HgCl₂(s) | Cl- (1.0 M) III. Ag(s) | AgCl(s) | Cl- (0.1 M) IV. Hg(l) | Hg₂Cl₂(s) | Cl- (1.0 M) V. Hg(s) | Hg₂Cl₂(s) | Cl- (1.0 M)

What is the cell potential for the following cell at 25°C? Al ∣ Al³⁺(0.00212 M) || Sn²⁺(0.435 M) ∣ Sn Al³⁺ + 3 e- → Al(s) E° = -1.676 V Sn²⁺ + 2 e- → Sn(s E° = -0.137 V

In a zinc-lead cell the reaction is: Pb²⁺ + Zn → Pb + Zn²⁺ E° = 0.637 V Which of the following statements about this cell is FALSE?

What is E° of the spontaneous cell made from the Zn²⁺/Zn (-0.76 V) and Br₂/2Br- (1.07 V) half cells?

Corrosion of metals is an oxidation-reduction process.

Determine E°cell for the reaction: Pb + Zn²⁺ → Pb²⁺ + Zn. The half reactions are: Pb2+(aq) + 2 e- → Pb(s) E° = -0.125 V Zn²⁺(aq) + 2 e- → Zn(s) E° = -0.763 V

For the reaction: Mg(s) + AgNO₃(aq) → Ag(s) + Mg(NO₃) ₂(aq) Ag⁺(aq) + e- → Ag(s) E° = 0.800 V Mg²⁺(aq) + 2 e- → Mg(s) E° = -2.356 V Determine ΔG°.

The Ecell for the following concentration cell at 25°C is 0.006. Pt ∣ H₂ (g, 0.025 atm) ∣ H⁺(0.012 M) = H⁺ (1 M) ∣ H₂ (g, 1 atm) ∣ Pt 2 H⁺(aq) + 2 e- → H₂(g) E° = 0. V

Consider the following reaction: 2 Al + 3 Ni2+ → 2 Al3+ + 3 Ni E° = 1.410 v What would be the cell potential at 25°C as calculated from the Nernst equation if [Ni2+] = 0.020 M, [Al3+] = 3.60 M?

Determine the Ksp at 25°C of AgCl(s) . The half-reactions are: Ag⁺(aq) + 1 e- → Ag(s) E° = +0.771 V AgCl(s) + 1 e- → Ag(s) + Cl- E° = +0.222 V

What is Keq at 25°C of the spontaneous cell made from the Zn²⁺/Zn (-0.76 V) and Br₂/2Br- (1.07 V) half cells?

What is the Ecell for the following cell at 25°C? Pt ∣ Fe²⁺ (0.0562 M) , Fe³⁺ (0.253 M) || Ag⁺ (0.334 M) ∣ Ag Ag⁺ + e- → Ag(s) E° = 0.800 V Fe³⁺ + e- → Fe₂⁺ E° = -0.771 V

In a galvanic cell, oxidation occurs at the:

Cathodic protection is attaching a more active metal to the protected metal.

Exam 20: Electrochemistry

Determine E°cell for the reaction: Cl2 + 2 F- → 2 Cl- + F2. The half reactions are: F2(s) + 2 e- → 2 F-(aq) E° = +2.866 V Cl2(s) + 2 e- → 2 Cl-(aq) E° = 1.358 V

For the reaction: Mg(s) + AgNO3(aq) → Ag(s) + Mg(NO3) 2(aq) Ag+(aq) + e- → Ag(s) E° = 0.800 V Mg2+(aq) + 2 e- → Mg(s) E° = -2.356 V For the reaction, determine E° for the cell.

For the reaction: Mg(s) + AgNO3(aq) → Ag(s) + Mg(NO3) 2(aq) Ag+(aq) + e- → Ag(s) E° = 0.800 V Mg2+(aq) + 2 e- → Mg(s) E° = -2.356 V Estimate Keq at 25°C.

Determine E°cell for the reaction: 2 Ag+ + Mg → 2 Ag + Mg2+. The half reactions are: Mg2+(aq) + 2 e- → Mg(s) E° = -2.356 V Ag+(aq) + e- → Ag(s) E° = 0.800 V

What is the cell potential for the following cell at 25°C? Zn ∣ Zn2+ (0.0456 M) || Cu2+(0.120 M) ∣ Cu Cu2+ + 2 e- → Cu(s) E° = 0.340 V Zn2+ + 2 e- → Zn(s) E° = -0.763 V

Which of the following are commonly used as alternate standard electrodes: I. Ag(s) | AgCl(s) | Cl- (1.0 M) II. Hg(l) | HgCl2(s) | Cl- (1.0 M) III. Ag(s) | AgCl(s) | Cl- (0.1 M) IV. Hg(l) | Hg2Cl2(s) | Cl- (1.0 M) V. Hg(s) | Hg2Cl2(s) | Cl- (1.0 M)

What is the cell potential for the following cell at 25°C? Al ∣ Al3+(0.00212 M) || Sn2+(0.435 M) ∣ Sn Al3+ + 3 e- → Al(s) E° = -1.676 V Sn2+ + 2 e- → Sn(s E° = -0.137 V

In a zinc-lead cell the reaction is: Pb2+ + Zn → Pb + Zn2+ E° = 0.637 V Which of the following statements about this cell is FALSE?

What is E° of the spontaneous cell made from the Zn2+/Zn (-0.76 V) and Br2/2Br- (1.07 V) half cells?

Corrosion of metals is an oxidation-reduction process.

For the following voltaic cell, determine the [Cl-] when PCl2 = 0.500 atm, [Zn2+] = 1.77 × 10-2 M, and Ecell = 2.250 V. The half-reactions at 25°C are: Cl2(g) + 2 e- → 2 Cl-(aq) E° = +1.358 V Zn2+(aq) + 2 e- → Zn(s) E° = -0.763 V Zn(s) ∣ Zn2+(aq) || Cl-(aq) , Cl2(g) ∣ Pt(s)

Determine E°cell for the reaction: Pb + Zn2+ → Pb2+ + Zn. The half reactions are: Pb2+(aq) + 2 e- → Pb(s) E° = -0.125 V Zn2+(aq) + 2 e- → Zn(s) E° = -0.763 V

For the reaction: Mg(s) + AgNO3(aq) → Ag(s) + Mg(NO3) 2(aq) Ag+(aq) + e- → Ag(s) E° = 0.800 V Mg2+(aq) + 2 e- → Mg(s) E° = -2.356 V Determine ΔG°.

The Ecell for the following concentration cell at 25°C is 0.006. Pt ∣ H2 (g, 0.025 atm) ∣ H+ (0.012 M) = H+ (1 M) ∣ H2 (g, 1 atm) ∣ Pt 2 H+(aq) + 2 e- → H2(g) E° = 0. V

Consider the following reaction: 2 Al + 3 Ni2+ → 2 Al3+ + 3 Ni E° = 1.410 v What would be the cell potential at 25°C as calculated from the Nernst equation if [Ni2+] = 0.020 M, [Al3+] = 3.60 M?

Determine the Ksp at 25°C of AgCl(s) . The half-reactions are: Ag+(aq) + 1 e- → Ag(s) E° = +0.771 V AgCl(s) + 1 e- → Ag(s) + Cl- E° = +0.222 V

What is Keq at 25°C of the spontaneous cell made from the Zn2+/Zn (-0.76 V) and Br2/2Br- (1.07 V) half cells?

What is the Ecell for the following cell at 25°C? Pt ∣ Fe2+ (0.0562 M) , Fe3+ (0.253 M) || Ag+ (0.334 M) ∣ Ag Ag+ + e- → Ag(s) E° = 0.800 V Fe3+ + e- → Fe2+ E° = -0.771 V

In a galvanic cell, oxidation occurs at the:

Cathodic protection is attaching a more active metal to the protected metal.

Determine E°cell for the reaction: Cl₂ + 2 F- → 2 Cl- + F₂. The half reactions are: F₂(s) + 2 e- → 2 F-(aq) E° = +2.866 V Cl₂(s) + 2 e- → 2 Cl-(aq) E° = 1.358 V

For the reaction: Mg(s) + AgNO₃(aq) → Ag(s) + Mg(NO₃) ₂(aq) Ag⁺(aq) + e- → Ag(s) E° = 0.800 V Mg²⁺(aq) + 2 e- → Mg(s) E° = -2.356 V For the reaction, determine E° for the cell.

For the reaction: Mg(s) + AgNO₃(aq) → Ag(s) + Mg(NO₃) ₂(aq) Ag⁺(aq) + e- → Ag(s) E° = 0.800 V Mg₂+(aq) + 2 e- → Mg(s) E° = -2.356 V Estimate Keq at 25°C.

What is the cell potential for the following cell at 25°C? Zn ∣ Zn²⁺ (0.0456 M) || Cu²⁺(0.120 M) ∣ Cu Cu²⁺ + 2 e- → Cu(s) E° = 0.340 V Zn²⁺ + 2 e- → Zn(s) E° = -0.763 V

Which of the following are commonly used as alternate standard electrodes: I. Ag(s) | AgCl(s) | Cl- (1.0 M) II. Hg(l) | HgCl₂(s) | Cl- (1.0 M) III. Ag(s) | AgCl(s) | Cl- (0.1 M) IV. Hg(l) | Hg₂Cl₂(s) | Cl- (1.0 M) V. Hg(s) | Hg₂Cl₂(s) | Cl- (1.0 M)

What is the cell potential for the following cell at 25°C? Al ∣ Al³⁺(0.00212 M) || Sn²⁺(0.435 M) ∣ Sn Al³⁺ + 3 e- → Al(s) E° = -1.676 V Sn²⁺ + 2 e- → Sn(s E° = -0.137 V

In a zinc-lead cell the reaction is: Pb²⁺ + Zn → Pb + Zn²⁺ E° = 0.637 V Which of the following statements about this cell is FALSE?

What is E° of the spontaneous cell made from the Zn²⁺/Zn (-0.76 V) and Br₂/2Br- (1.07 V) half cells?

Determine E°cell for the reaction: Pb + Zn²⁺ → Pb²⁺ + Zn. The half reactions are: Pb2+(aq) + 2 e- → Pb(s) E° = -0.125 V Zn²⁺(aq) + 2 e- → Zn(s) E° = -0.763 V

For the reaction: Mg(s) + AgNO₃(aq) → Ag(s) + Mg(NO₃) ₂(aq) Ag⁺(aq) + e- → Ag(s) E° = 0.800 V Mg²⁺(aq) + 2 e- → Mg(s) E° = -2.356 V Determine ΔG°.

The Ecell for the following concentration cell at 25°C is 0.006. Pt ∣ H₂ (g, 0.025 atm) ∣ H⁺(0.012 M) = H⁺ (1 M) ∣ H₂ (g, 1 atm) ∣ Pt 2 H⁺(aq) + 2 e- → H₂(g) E° = 0. V

Determine the Ksp at 25°C of AgCl(s) . The half-reactions are: Ag⁺(aq) + 1 e- → Ag(s) E° = +0.771 V AgCl(s) + 1 e- → Ag(s) + Cl- E° = +0.222 V

What is Keq at 25°C of the spontaneous cell made from the Zn²⁺/Zn (-0.76 V) and Br₂/2Br- (1.07 V) half cells?

What is the Ecell for the following cell at 25°C? Pt ∣ Fe²⁺ (0.0562 M) , Fe³⁺ (0.253 M) || Ag⁺ (0.334 M) ∣ Ag Ag⁺ + e- → Ag(s) E° = 0.800 V Fe³⁺ + e- → Fe₂⁺ E° = -0.771 V