Chemistry 40S
Electrochemistry Review Questions
1. The net equation for a given voltaic cell is:
Sn (s) + 2 Ag+  Sn2+ + 2 Ag (s)
a. Write the two half-reactions involved, and identify each in terms of (1)
site of oxidation or reduction and (2) anode or cathode.
b. Calculate the net potential of the cell (the voltage), assuming standard
conditions.
c. Draw a fully labeled diagram of the voltaic cell. Be sure to indicate the
flow of electrons in the external circuit (through the wire) and the flow
of ions in the solution.
Chemistry 40S
2. The following questions pertain to a voltaic cell in which the following halfreactions occur:
S (s) + 2e-  S2- (aq)
Ca2+ (aq) + 2e-  Ca (s)
a) Which half-reaction will proceed as a reduction? Which will proceed as an
oxidation? How do you know?
b) Rewrite the half-reactions in the correct directions.
c) Write a balanced equation for the overall cell reaction.
d) Calculate the cell potential.
3. A voltaic cell is constructed using electrodes based on the following half
reactions:
Pb2+ (aq) + 2e- -> Pb(s)
Au3+(aq) +3e- -> Au(s)
a) Which is the anode and which is the cathode in this cell?
b) What is the cell potential?
Chemistry 40S
4. A voltaic cell is constructed using electrodes based on the following half
reactions:
Mn2+ (aq) + 2e- -> Mn(s)
Cu2+ (aq) +2e- -> Cu(s)
a) Which is the anode and which is the cathode in this cell?
b) What is the standard cell potential?
5. Indicate whether the following reactions are spontaneous or not and what
the reaction potential between the substances are.
a) Zn + HCl
b) Mg + FeCl2
c) Pb + SnCl2
d) Mg + Fe SO4
e) Ag + Cu(NO3)2
f) Al + CuSO4
Chemistry 40S
g) Zn + AgNO3
h) Mg + Fe(NO3)2
i) Mg + NaCl
j) FeSO4 +
Cu
6. Write the appropriate half reactions, which metal is the cathode/anode,
and calculate the cell potential for each of the following electrochemical cells.
a) Copper and aluminum
b) Silver and zinc
c) Copper and nickel
d) Nickel and cadmium
e) Silver and aluminum
Chemistry 40S
7. Given the following experimental data, arrange the following in an activity
series.
Co2+ + In(s) → Co(s) + In2+
Cu2+ + Co(s) → Cu(s) + Co2+
Cu2+ + Pd(s) → no reaction
8. Predict the products and which electrode they are produced at in an
electrolytic cell containing:
a) Aqueous sodium chloride
b) Molten lithium iodide
c) Molten tin(II) sulfide
d) Aqueous iron (III) oxide
Chemistry 40S
Electrochemistry Review Questions
1. The net equation for a given voltaic cell is:
Sn (s) + 2 Ag+  Sn2+ + 2 Ag (s)
a. Write the two half-reactions involved, and identify each in terms of (1)
site of oxidation or reduction and (2) anode or cathode.
Sn(s)  Sn2+ + 2eAg+ + e-  Ag(s)
 Oxidation, anode
 Reduction, cathode
b. Calculate the net potential of the cell (the voltage), assuming standard
conditions.
Eo = 0.94 V
d. Draw a fully labeled diagram of the voltaic cell. Be sure to indicate the
flow of electrons in the external circuit (through the wire) and the flow
of ions in the solution.
In this drawing, replace copper with tin
Chemistry 40S
2. The following questions pertain to a voltaic cell in which the following halfreactions occur:
Cu+ (aq) + 1e-  Cu (s)
Ca2+ (aq) + 2e-  Ca (s)
a) Which half-reaction will proceed as a reduction? Which will proceed as an
oxidation? How do you know?
Calcium will be oxidized and copper will be reduced, since Ca(s) is
up and to the right from Cu+
b) Rewrite the half-reactions in the correct directions.
Ca(s)  Ca2+ + 2eCu+ + 1e-  Cu(s)
c) Write a balanced equation for the overall cell reaction.
2Cu+ + Ca(s)  Ca2+ + 2Cu(s)
d) Calculate the cell potential.
Eo = 3.39 V
3. A voltaic cell is constructed using electrodes based on the following half
reactions:
Pb2+ (aq) + 2e- -> Pb(s)
Au3+(aq) +3e- -> Au(s)
a) Which is the anode and which is the cathode in this cell?
Anode: lead
b) What is the cell potential?
Eo = 1.63 V
Cathode: gold
Chemistry 40S
4. A voltaic cell is constructed using electrodes based on the following half
reactions:
Mn2+ (aq) + 2e- -> Mn(s)
Cu2+ (aq) +2e- -> Cu(s)
a) Which is the anode and which is the cathode in this cell?
Anode: Mn
Cathode: Cu
b) What is the standard cell potential?
Eo = 1.52 V
5. Indicate whether the following reactions are spontaneous or not and what
the reaction potential between the substances are.
a) Zn + HCl
Spontaneous  Eo = 0.76 V
b) Mg + FeCl2
Spontaneous  Eo = 1.93 V
c) Pb + SnCl2
Non-spontaneous  Eo = -0.01 V
d) Mg + Fe SO4
Spontaneous  Eo = 1.93 V
e) Ag + Cu(NO3)2
Non-spontaneous  Eo = -0.46 V
f) Al + CuSO4
Spontaneous  Eo = 2.00 V
Chemistry 40S
g) Zn + AgNO3
Spontaneous  Eo = 1.56 V
h) Mg + Fe(NO3)2
Spontaneous  Eo = 1.93 V
i) Mg + NaCl
Non-spontaneous  Eo = -0.34 V
j) FeSO4 +
Cu
Non-spontaneous  Eo = -0.78 V
6. Write the appropriate half reactions, which metal is the cathode/anode,
and calculate the cell potential for each of the following electrochemical cells.
a) Copper and aluminum
Cathode: Cu2+ + 2e-  Cu(s)
Anode: Al(s)  Al3+ + 3e-
Eo = 2.18 V
b) Silver and zinc
Cathode: Ag+ + 1e-  Ag(s)
Anode: Zn(s)  Zn2+ + 2e-
Eo = 1.56 V
c) Copper and nickel
Cathode: Cu2+ + 2e-  Cu(s)
Anode: Ni(s)  Ni2+ + 2e-
Eo = 0.59 V
d) Nickel and cadmium
Cathode: Ni2+ + 2e-  Ni(s)
Anode: Cd(s)  Cd2+ + 2e-
Eo = 0.15 V
e) Silver and aluminum
Cathode: Ag+ + 1e-  Ag(s)
Anode: Al(s)  Al3+ + 3e-
Eo = 2.46 V
Chemistry 40S
7. Given the following experimental data, arrange the following in an activity
series.
Co2+ + In(s) → Co(s) + In2+
Cu2+ + Co(s) → Cu(s) + Co2+
Cu2+ + Pd(s) → no reaction
In2+ + 2e-  In(s)
Co2+ + 2e-  Co(s)
Cu2+ + 2e-  Cu(s)
Pd2+ + 2e-  Pd(s)
8. Predict the products and which electrode they are produced at in an
electrolytic cell containing:
a) Aqueous sodium chloride
Cathode: OH- and H2(g)
Anode: O2(g) and H+
b) Molten lithium iodide
Cathode: Li(s)
Anode: I2(s)
c) Molten tin(II) sulfide
Cathode: Sn(s)
Anode: S(s)
d) Aqueous iron (III) oxide
Cathode: Fe(s)
Anode: O2(g) and H+