Question

The time required for a current of $3$ amp. to decompose electrolytically $18$g of $H_{2}O$ is:

• A. $18$ hour
• B. $36$ hour
• C. $9$ hour
• D. $18$ seconds

Answer 1

The correct option is A $18$ hour

According to Faraday first law $W\propto Q$

and $W=\frac{Ewt}{F}$

$Ewt.=$ Equivalent weight

$F=$ Faraday constant

$W=$ weight

$Q=$ $current\left(i\right)\times time\left(t\right)$

$\frac{W}{Ewt}=\frac{it}{F}$

$\frac{18\times 2}{18}=\frac{3\times t}{96500}(Ewt=\frac{M.w.}{V.F.})$

$\frac{2\times 96500}{3\times 3600}=t$

$t=64333s\approx 18hr$

The correct option is [A].