Explain the principle of electrolytic refining with an example.

Explanation

The crude metal is refined by electrolysis.It is carried out in an electrolytic cell containing aqueous solution of the salts of the metal of intrest.The impure metal are used as anode and thin strips of pure metal are used as cathode.During electrolysis,the less electropositive impurities in the anode ,settle down at the bottom and are removed as anode mud.
Let us understand this process by considering eletrolytic refining of silver as an example.
Cathod:Pure ilver
Anode:Impure silver rods
Electrolyte:Acidified solution of silver nitrate.
When a current is passed though the electrodes the following reactions will take place reaction at anode:2g(s)`toAg^(+)(aq)+"le"^(-)`Reaction at cathode:`Ag^(+)(aq)+"le"^(-)toAg(s)`
During electrolysis ,at the silver atoms lose electrons and enter the solution.The positively charged silver cations migrate towards the cathods and get discharged by gaining electrons and deposited on the cathode .Other metals such as copper,zinc etc.,can also be refined by this process in a similar manner.