Question

State the products of electrolysis obtained on the cathode and the anode in the following cases:
(i) A dilute solutoin of `H_(2)SO_(4)` with platinum electrodes
(ii) An aqueous solution of `AgNO_(3)` with silver electrodes.

Answer 1

(i) `H_(2)SO_(4)(aq)to2H^(+)(aq)+SO_(4)^(2-)(aq)," "H_(2)OhArrH^(+)+OH^(-)`
At cathode: `H^(+)+etoH,H+HtoH_(2)(g)`
At anode: `OH^(-)toOH+e^(-),4OHto2H_(2)O(l)+O_(2)(g)`
Thus, `H_(2)` is liberated at the cathode and `O_(2)` at anode.
(ii) `AgNO_(4)(s)+aqtoAg^(+)(aq)+NO_(3)^(-)(aq)," "H_(2)OhArrH^(+)+OH^(-)`.
At cathode. `Ag^(+)` ions ahve lower discharge potential than `H^(+)` ions. hence, `Ag^(+)` ions will be deposited on the cathode `(Ag^(+)+e^(-)toAg)`
At anode. Ag anode will be attached by `NO_(3)^(-)` ions. hence, Ag anode will dissolve to form `Ag^(+)` ions in the solution `(AgtoAg^(+)+e^(-))`