Q. When 1 F of electricity is passed through acidulated water, $O_{2}$ evolved is
A) ${11.2\ dm}^{3}$
B) ${5.6\ dm}^{3}$
C) ${22.4\ dm}^{3}$
D) ${1.0\ dm}^{3}$
Explanation
(b)
${2H}_{2}O\ \rightleftharpoons \ {4H}^{+} + \ {2O}^{2 -}$
At cathode, ${4H}^{+}\ + \ {4e}^{-}\ \rightarrow \ {2H}_{2}$
At anode, ${2O}^{2 -}\ - \ {4e}^{-}\ \rightarrow \ O_{2}$
∴ 4 Faraday of charge liberates = 1 mol
$= \ 22.4\ {dm}^{3}O_{2}$
∴ 1 Faraday of charge liberates
$= \ \frac{22.4}{4}\ \times \ 1$
$= \ 5.6\ {dm}^{3}O_{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.