Which of the following on electrolysis would, not evolve oxygen at the anode ?

Options

A. Dilute `H_(2)SO_(4)` with Pt electrodes
B. Aqueous silver nitrate using Pt electrodes
C. Aqueous `Na_(2)SO_(4)` with Pt electrodes
D. 50 % `H_(2)SO_(4)` with Pt electrodes

Answer

D

Explanation

On electrolysis of 50 % `H_(2)SO_(4)`
`H_(2)SO_(4)rarrH^(+)+HSO_(4)^(-)2H^(+)+2e^(-)rarrH_(2)uparrow("cathode")`
`2HSO_(4)^(-)rarrH_(2)S_(2)O_(8)+2e^(-)("anode")`