The electrolysis of an aqueous solution of copper sulphate using copper electrodes (i.e. using active electrodes) results in transfer of copper metal from the anode to the cathode during electrolysis. The copper sulphate is ionised in aqueous solution.
CuSO4 - -> Cu2+ + S
The positively charged copper ions migrate to the cathode, where each gains two electrons to become copper atoms that are deposited on the cathode.
Cathode: Cu2+ + 2e → Cu
At the anode, each copper atom loses two electrons to become copper ions, which go into solution.
Anode: Cu → Cu2+ + 2e
The sulphate ion does not take part in the reaction and the concentration of the copper sulphate in solution does not change. The reaction is completed when the anode is completely eaten away. This process is used in electroplating
= 1.05 V – 0.0295 x log 80
= 1.05 V – 0.0295 x 1.9031
= 1.05 V – 0.056 = 0.99 V.