Question

An aqueous solution with of sodium nitrate with platinum electrodes

Answer 1

At the cathode (C), water is reduced to hydroxide and hydrogen gas. The net process is the electrolysis of an aqueous solution of NaCl into industrially useful products sodium hydroxide (NaOH) and chlorine gas.

Answer 2

When a dilute aqueous solution of sodium chloride is electrolysed between platinum electrodes, hydrogen gas is evolved at cathode but metallic sodium is not deposited. It is because, sodium is much below in the activity series, hydrogen is discharged at the cathode.