Question

The quantity of electricity required to liberate $112\,cc$ of hydrogen at STP from acidified water is

• A. 965 C
• B. 4825 C
• C. 9650 C
• D. 96500 C

Answer 1

Answer: (A)

$\underset{1 \text { mole }}{ H _{2} O } \longrightarrow \underset{1 \text { mole of } H _{2}}{2 H ^{+}}+\frac{1}{2} O _{2}+\underset{2 \text { moles }}{2 e ^{-}}$
$1$ mole of $H _{2}=2$ Faradays of electricity
$22490\, cc $of $H 2=2 \times 96500 C$
$112 \,cc$ of $H _{2}=\frac{2 \times 96500}{22400} \times 112$
$=965 \,C$ of electricity