Electrochemistry 1 Question 43
42. Calculate the quantity of electricity that would be required to reduce $12.3 \mathrm{~g}$ of nitrobenzene to aniline, if the current efficiency for the process is $50 %$. If the potential drop across the cell is $3.0 \mathrm{~V}$, how much energy will be consumed?
(1990, 3M)
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Answer:
Correct Answer: 42. $(347.40 \mathrm{~kJ})$
Solution:
42.
Change in oxidation number at nitrogen $=4-(-2)=6$
Equivalent weight of nitrobenzene $=\frac{123}{6} \mathrm{~g}$ $\Rightarrow$ gram equivalent of nitrobenzene $=\frac{12.3 \times 6}{123}=0.60$
$\Rightarrow$ Theoretical requirement $=0.60 \times 96500 \mathrm{C}=57900 \mathrm{C}$
$\Rightarrow$ Actual requirement of electricity $=2 \times 57900=115800 \mathrm{C}$
$\because \quad V \times C=J$
$\Rightarrow$ Energy consumed $=115800 \times 3 \mathrm{~J}=347.40 \mathrm{~kJ}$
