Question

Name two metals that are purified by electrolytic decomposition. Mention the anode, cathode and the electrolyte used in the refining process. At which electrode would be the pure metal deposited?

Answer 1

Copper and zinc are purified by electrolytic process.

Electrodes:

Pure metal i.e. copper or zinc is used at cathode while impure metal is used at anode.

Anode:

M → Mn+ + ne–

i.e.

Cu→ Cu²⁺+2e^-

and

Zn→ Zn²⁺+2e^-

Cathode: Mn+ + ne– → M

i.e.

Cu²⁺+2e^-→Cu

and

Zn²⁺+2e^-→Zn

Electrolytes:

Copper sulphate and zinc sulphate