Question

Which statement about electrolysis reactions is correct?

• A. When concentrated aqueous sodium chloride is electrolysed, sodium forms at the cathode.
• B. When concentrated hydrochloric acid is electrolysed, a green gas forms at the cathode.
• C. When dilute sulphuric acid is electrolysed, a colourless gas forms at both electrodes.
• D. When molten lead (II) bromide is electrolysed, lead forms at the anode.

Answer 1

The correct option is C When dilute sulphuric acid is electrolysed, a colourless gas forms at both electrodes.

Solution:- (C) When dilute sulfuric acid is electrolysed, a colourless gas forms at both electrodes.

Dilute sulfuric acid can be electrolysed to form hydrogen gas at the cathode and oxygen gas at the anode.

Reaction at anode:-

$4O{H}^{-}⟶2H_{2}O+O_2\left(g\right)+4e^{-}$

Reaction at cathode:-

$2H^{+}+2e^{-}⟶H_2\left(g\right)$