On electrolysis in which of the following, `O_(2)` would be liberated at the anode?

Options

A. dilute `H_(2)SO_(4)` with Pt electrodes
B. aqueous `AgNO_(3)` solution with Pt electrodes
C. dilute `H_(2)SO_(4)` with Cu electrodes
D. aqueous NaOH with a Fe cathode & a Pt anode

Answer

A, B, D

Explanation

(A). Anode ,`2H_(2)OtoO_(2)+4H^(+)+4e^(-)`
(B). Anode, `2H_(2)OtoO_(2)+4H^(+)+4e^(-)`
(C). Anode: `CutoCu^(2+)+2e^(-)`
(D). Anode, `2H_(2)OtoO_(2)+4H^(+)+4e^(-)`