Chem 30
Faraday’s Law
1. A student builds a Daniell cell using half-cells of copper and zinc, and a current of
0.500 A is produced for 22.0 min. Predict the mass of zinc oxidized to aqueous zinc
ions.
(0.224 g)
2. A car bumper is plated with chromium using chromium(III) ions in solution. If a
current of 54.2 A flows in the cell for 45.5 minutes, predict the mass of chromium
deposited on the bumper.
(26.6 g)
3. For corrosion resistance, a steel bolt is plated with nickel from a solution of nickel(II)
sulfate. If 4.25 g of nickel produces a plating of the required thickness, how long (in
hours) will this process take if a 720 mA current is used?
(5.39 h)
4. A family wishes to plate an antique teapot with 10.00 g of silver. If the process takes
84 min, what average current has been used?
(1.8 A)
5. The anode half-reaction in a car battery is shown below:
Pb(s) + SO42−(aq) → PbSO4(s) + 2 e−
A car battery can produce a 1.00 A current for 120 h. What mass of lead is oxidized
as this battery completely discharges?
(464 g)
6. If an aluminum – oxygen fuel cell produces the same current for the same length of
time as the car battery in question #5, then what mass of aluminum would be
oxidized?
(40.3 g)
7. During the electrolysis of molten aluminum chloride in an electrolytic cell, 5.40 g of
aluminum is produced at the cathode. Predict the mass of chlorine produced at the
anode.
(21.3 g)