CHEM 160
Electrochemistry
Ch. 20 Example Problems
This list of thermodynamics chemistry problems contains problems that will be worked as examples in class
and additional problems for students to try on their own.
1. A voltaic cell is made by connecting a standard Cu/Cu2+ electrode with a SHE. The cell
potential is 0.34 V. The copper electrode serves as the cathode. Calculate the standard
reduction potential of the Cu/Cu2+ electrode. (ans.: 0.34 V)
2. A voltaic cell is made by connecting a standard Zn/Zn2+ electrode with a SHE. The cell
potential is 0.76 V, with the SHE serving as the cathode. Calculate the standard
reduction potential of the Zn/Zn2+ electrode. (ans.: -0.76 V)
3. A voltaic cell consists of a Ag electrode in 1.0 M AgNO3 and a Cu electrode in 1.0 M
Cu(NO3)2. Calculate E°cell for a spontaneous cell reaction at 25°C. (ans.: 0.46 V)
4. A voltaic cell consists of a Ni electrode in 1.0 M Ni(NO3)2 and a Fe electrode in 1.0 M
Fe(NO3)3. Calculate E°cell for a spontaneous cell reaction at 25°C. (ans.: 0.16 V)
5. Calculate ∆G° at 25°C for the redox reaction between Sn4+ and Fe that takes place in a
voltaic cell if E°cell = 0.60 V. The reaction is: Sn4+(aq) + Fe(s) → Fe2+(aq) + Sn2+(aq).
(ans.: -116 kJ)
6. Calculate E°cell, ∆G°rxn, and K for the reaction of Ag and Cl2 under standard state
conditions. Is this reaction spontaneous?
(ans.: E°cell = 0.56 V; ∆G° = -1.08 x 105 J; K = 8.8 x 1018)
7. Calculate the voltage produced by the voltaic cell using the reaction between Zn and Cu2+
if [Zn2+] = 0.001 M and [Cu2+] = 1.3 M. (ans.: 1.19 V)
8. Calculate the voltage produced by the voltaic cell which uses the following reaction if
[Ag+] = 0.001 M and [Cu2+] = 1.3 M: 2Ag+ + Cu ⇔ Cu2+ + 2Ag. (ans.: 0.28 V)
9. What mass of Cu can be produced by a 3.00 A current flowing through a CuSO4 solution
for 5.00 hours? (ans.: 18g V)
10. An aqueous solution of an iron salt is electrolyzed by passing a current of 2.50 A for 3.50
hours. As a result, 6.1 g of Fe(s) are formed at the cathode. Calculate the charge on the
iron ions in the solution. (ans.: +3)
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