Question

Refining of impure copper with zinc impurity is to be done. The appropriate electrodes are:

• A. Cathode- Pure Zinc
  Anode - Pure Copper
• B. Cathode- Pure Copper
  Anode - Pure Zinc
• C. Cathode- Pure Copper
  Anode - Impure Copper
• D. Cathode- Pure Zinc
  Anode - Impure Zinc

Answer 1

The correct option is C Cathode- Pure Copper

Anode - Impure Copper
Refining of pure copper is done by electrolytic method.
In this method anode is of impure copper and pure copper strips are taken as cathode. The electrolyte is acidified solution of copper sulphate and the net result of electrolysis is the transfer of copper in pure form from the anode to cathode. Reactions occur at each electrode are as follows
Anode:
$Cu\left(s\right)+2e^{-}\to C{u}^{2+}\left(aq\right)$
Cathode:
$C{u}^{2+}+2e^{-}\left(aq\right)\to Cu\left(s\right)$
Impurities (of other metals) from the impure copper deposit as anode mud.