Question

During electrolysis of an aqueous solution of sodium sulphate, 2.4 L of oxygen at STP was liberated at anode. The volume of hydrogen at STP, liberated at cathode would be:

• A. 1.2 L
• B. 2.4 L
• C. 2.6 L
• D. 4.8 L

Answer 1

The correct option is D 4.8 L

Reaction at anode:
$2O^{-2}\to O_2+4e^{-}$ and

At cathode:
$2H^{+}+2e^{-}\to H_2$

So double charge is released at anode and half is used at the cathode.

So, according to faraday's law:
$W=ZQ$
So twice mass will be released at the cathode.
So 4.8 litre of hydrogen gas liberated at the cathode.

Hence, option D is correct.