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)

965 C

Answer 2

{\underset{\text{1 mole}}{{ H_2 O }}$->$\underset{\text{1 mole of H_2}}{{2H^+ }}$+ \frac{1}{2} O_2 +$\underset{\text{2 moles}}{{2e^- }}}
${1 \, mole\, of\, H_2 = 2}$ 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