Question

If $9 \,g$ of $H _{2} O$ is electrolyzed completely with $50 \%$ current efficiency

• A. $1 \,F$ of electricity will be needed
• B. $3 \,F$ of electricity is needed
• C. $5.6 \,L$ of $O _{2}$ at STP will be formed
• D. $11.2\, L$ of $O _{2}$ at STP will be formed

Answer 1

Answer: (C)

for $36 \,g \, H _{2} O$ volume of $O _{2} \rightarrow \frac{22.4}{2}=11.2$ litre
So, $9 \,g \, H _{2} O$ volume of $O _{2} \rightarrow \frac{11.2}{36} \times 9=2.8 L$
$50 \%$ current efficiency $2$ mole of $O _{2} \rightarrow 5.6$ litre