Question

Calculate the quantity of electricity that would be required to reduce $12.3g$ of nitrobenzene to aniline, if the current efficiency for the process is $50\%$. If the potential drop across the cell is $3.0V$, how much energy will be consumed?

Answer 1

Change in oxidation number at nitrogen = 4 - (- 2) = 6
Equivalent weight of nitrobenzene $=\frac{123}{6}g$
$\Rightarrow$ gram equivalent of nitrobenzene $=\frac{12.3\times 6}{123}=0.60$
$\Rightarrow$ Theoretical requirement $=0.60\times 96500C=57900C$
$\Rightarrow$ Actual requirement of electricity $=2\times 57900=115800C$
$\because V\times C=J$
$\Rightarrow$ Energy consumed $115800\times 3J=347.40kJ$