Question

During the electrolysis of molten sodium chloride, the time to produce 0.10 mol of chlorine gas using a current of 3 amperes is

• A. 55 minutes
• B. 110 minutes
• C. 220 minutes
• D. 330 minutes

Answer 1

The correct option is B 110 minutes

During the electrolysis of molten sodium chloride,
At cathode: $2N{a}^{+}+2e^{-}\to 2Na$
At anode: $2C{l}^{-}\to C{l}_2+2e^{-}$
(Net reaction:$2N{a}^{+}+2C{l}^{-}\to 2Na+C{l}_2{)}^{-}$
According to Faraday’s first law of electrolysis,
$w=Z\times I\times t$
$w=\frac{E}{96500}\times I\times t$
No of moles of $C{l}_2$ gas $\times$ Mol.wt.of $C{l}_2$ gas
$=\frac{Eq.wt.ofC{l}_{2}gas\times I\times t}{96500}$
$0.10\times 71=\frac{35.5\times 3\times t}{96500}$
$t=\frac{0.10\times 71\times 96500}{35.5\times 3}=6433.33sec$
$t=\frac{6433.33}{60}min=107.22min\approx 110min$