Electrolysis of aqueous solution of ammonium sulphate and sulphuric acid at anode gives

Explanation

During the electrolysis of aqueous `K_(2)SO_(4)` , the chemical changes involved are,
At anode (oxidation of water ) `=2H_(2)O_((l)) rarr O_(2)+4e^(-)+ 4H_((aq))^(+)`
At cathode (reduction of water) `=2H_(2)O_((l))+2e^(-) rarr H_(2(g))+2OH_((aq))^(-)`
Solution is acidic around anode and litmus is red. Solution is basic around cathode and litmus is blue.