Question

Total volume of gases evolved at STP when 36g of $H_{2}O$ are completely electrolyzed between platinum electrodes:

• A. 22.4 lit
• B. 44.8 lit
• C. 33.6 lit
• D. 67.2 lit

Answer 1

The correct option is D 67.2 lit

$Molesof{H}_{2}O=\frac{36}{18}=2$

$2H_{2}O\underset{–}{electricity}2H_2+O_2$

2 moles $H_{2}O$ gives $2+1=3$ moles gases
$\therefore$ At STP, 1 mole gas occupies 22.4 L
$\therefore 3molesoccupies=3\times 22.4=67.2L$