Question

In the electrolysis of alkaline water,a total of 1 mol of gases is evolved.The amount of water decomposed would be

Answer 1

2H2O-------->2H2 +O2. i.e, 3 moles of gas is produced by 2 moles of water . Therefore , 1mole of gas will be produced by 2/3 moles of water . Hope it helps

Answer 2

Answer: The amount of water decomposed would be 12 g.

Explanation:

$2H_2O\rightarrow O_2+2H_2$

Divide the while equation by 2

$H_2O\rightarrow \frac{1}{2}O_2+H_2$

Total moles of gases evolved= $\frac{1}{2} moles+1 moles=\frac{3}{2} moles$

$\frac{3}{2} moles$ of gases are produced from 1 mole of water on decomposition

Then 1 mole of gases will be obtained from:$\frac{2}{3}\times 1$ moles of water that $\frac{2}{3}$ moles

Mass of water = Moles of water × Molar mass of water

$\frac{2}{3} moles\times 18 g/mol=12 g$

The amount of water decomposed would be 12 g.