A student performs an electrolysis of an aqueous CuSO₄ solution using copper electrodes
CHEMISTRY · Multi-part · AP · Chemistry · Thermodynamics and Electrochemistry · Thermodynamics and Electrochemistry
Problem
A student performs an electrolysis of an aqueous CuSO₄ solution using copper electrodes. After operating the cell at a steady current for exactly 30.0 minutes, the student predicts that 0.50 g of copper should be deposited on the cathode but measures only 0.42 g of additional mass on that electrode.
(a) Describe two possible physical or chemical reasons that could account for the difference between the predicted and measured masses.
(b) For each reason you listed in part (a), explain qualitatively how it would decrease the amount of copper actually deposited without altering the amount of charge that passed through the cell.
(c) Propose one specific procedural modification to the experimental setup that would be expected to increase the percent yield of copper deposition, and justify your proposal based on electrochemical principles.