The metals produced by various reduction processes are not very pure. They contain impurities, which must be removed to obtain pure metals. The most widely used method for refining impure metals is electrolytic refining. (i) What is the cathode and anode made of in the refining of copper by this process? (ii) Name the solution used in the above process and write its formula. (iii) (A) How copper gets refined when electric current is passed in the electrolytic cell? OR (iii) (B) You have two beakers 'A' and 'B' containing copper sulphate solution. What would you observe after about 2 hours if you dip a strip of zinc in beaker 'A' and a strip of silver in beaker 'B'? Give reason for your observations in each case.

(i) In the electrolytic refining of copper, the anode is made of a thick block of impure copper, and the cathode is made of a thin strip of pure copper.

(ii) The electrolyte solution used is an acidified solution of copper sulphate ($CuSO_4$).

(iii) (A) When an electric current is passed through the electrolyte, pure copper from the impure anode dissolves into the electrolyte. Simultaneously, an equivalent amount of pure copper from the electrolyte is deposited on the pure copper cathode. Soluble impurities go into the solution, while insoluble impurities settle at the bottom of the anode as anode mud.

OR

(iii) (B) In Beaker 'A', the blue colour of the copper sulphate solution will gradually fade, and a reddish-brown deposit of copper will be seen on the zinc strip. This is because zinc is more reactive than copper and displaces it from its solution ($Zn(s) + CuSO_4(aq) ightarrow ZnSO_4(aq) + Cu(s)$). In Beaker 'B', no change will be observed because silver is less reactive than copper and cannot displace it from copper sulphate solution.