Electrolysis is an impotant technique for extraction of metals, and each of the solution needs a minimum voltage to get discharged and this value is expressed in terms of discharge potential. For some metal ions the discharge potential follow the order given below:
`Li^(+) gt K^(+) gt Ca^(2+) gt Na^(+) gt Mg^(2+) gt Al^(3+) gt Zn^(2+) gt Fe^(2+) gt Ni^(2+)`
`H_(3)O gt Cu^(2+) gt H_(2)^(2+) gt Ag^(+) gt Au^(3+)`.
For some anions the discharge potentials:-
`SO_(4)^(2-) gt BO_(3)^(-) OH^(-) gt Br^(-) gt I^(-)`
The product formed at anode and cathode, when dilute `H_(2)SO_(4)` is electrolysed are:
A. `SO_(2),H_(2)`
B. `SO_(3),H_(2)`
C. `H_(2)S_(2)O_(8),H_(2)`
D. `O_(2),H_(2)`
