Question

During the electrolysis of molten sodium chloride, the time required to produce $0.10mole$ of chlorine gas using a current of $3amperes$ is: (select the approximate ans)

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

Answer 1

The correct option is B $110minutes$

During the electrolysis of molten sodium chloride, the following reaction is observed:
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
= $\frac{Eq.wt.ofC{l}_{2}gas\times I\times \times t}{96500}$

= $0.10\times 71=\frac{35.5\times 3\times t}{96500}$

$t=\frac{0.10\times 71\times 96500}{35.5\times 3}=6433.33sec$

$t=\frac{6433.33}{60}min$ = $107.22min$ ~$110min$
option $\left(b\right)$ has the approximate answer and thus it is correct