A research lab studies the electroplating of nickel from an aqueous Ni(NO₃)₂ solution
CHEMISTRY · Multi-part · AP · Chemistry · Thermodynamics and Electrochemistry · Thermodynamics and Electrochemistry
Problem
A research lab studies the electroplating of nickel from an aqueous Ni(NO₃)₂ solution. A constant current of 2.00 A is applied for 3.00 h. The mass of nickel actually deposited on the cathode is only 1.00 g, even though only Ni²⁺ ions were intended to be reduced. Assume the only significant side process is oxygen gas evolution at the anode.
(a) Calculate the theoretical mass of nickel that should have been deposited if all of the charge had been used exclusively for nickel reduction.
(b) Determine the percent yield for nickel deposition in this experiment.
(c) Using your answers from parts (a) and (b), calculate the fraction of the total charge that was consumed by the oxygen evolution side reaction.
(d) Propose one modification to the electrolysis conditions or cell design that could reduce the extent of the oxygen side reaction. Justify your proposal using electrochemical reasoning.