In which of the following aqueous solutions `H_(2)` and `O_(2)` are not liberated at cathode and anode respectively on electrolysis using inert electrodes?

Options

A. Molten NaCl
B. Concentrated aq. solution of NaCl
C. Dilute aq. solution. of NaCl
D. Solid NaCl

Answer

C

Explanation

For dilute aq. solution of NaCl
`NaCl(s)=Na^(+)(aq.)+Cl^(-)(aq)`
`H_2O(l)=H^(+)(aq)+OH^(-)(aq)`
At Cathode
`H^(+)` will discharge since the discharge potential of
`H^(+)ltNa^(+)`
`2H^(+)(aq.)+2e^(-)toH_2(g)`
At anode
Due to very lesser amount of `Cl^(-)OH^(-)` , ions will discharge at anode
`4OH^(-)(aq)toO_2(g)+2H_2O(l)+4e^(-)`