question_answer 69)

  During extraction of metals, electrolytic refining is used to obtain pure metals, (a)Which material will be used as anode and cathode for refining of silver metal by this process? (b) Suggest a suitable electrolyte also. (c) In this electrolytic cell, where do we get pure silver after passing electric current?        

Answer:

                  (a)Thin strip of pure silver is made the cathode (It is connected to the negative terminal of the battery). And impure, silver block is made anode (It is connected to the positive terminal of the battery). (b) The electrolyte is any salt solution of silver likebut sodium argent cyanideis preferred. (c) On passing electric current, impure metal dissolves from the anode and goes into the electrolyte solution and pure metal from the electrolyte deposits on the cathode.