Question

During electrolysis of water, the ratio (v/v) of the gas obtained at anode to that obtained at cathode is

• A. 1 : 4
• B. 4 : 1
• C. 1 : 2
• D. 2 : 1

Answer 1

The correct option is C 1 : 2

From the given reaction

$2H_{2}O\to 2H_2+O_2$


We can see that during electrolysis of water, 2 moles of hydrogen gas is obtained at cathode and 1 mole of oxygen gas is obtained at anode.

It is asked for the ratio of gas obtained at anode to cathode

Which means that $O_2:H_2=1:2$