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?

Explanation

`C_(6)H_(5)NO_(2)+6H^(+)+6e rarr C_(6)H_(5)NH_(2)+2H_(2)O`
`N^(3+)+6e rarr N^(3-)`
`:.` Eq. `wt.` of nitrobenzene `= (M)/(6) = (123)/(6)`
Since current efficiency is `50%`
`:. i = (50i_(0))/(100)`
Now `w = (E.i.t)/(96500)`
`12.3 = (123 xx i_(0) xx t xx 50)/(6 xx 100 xx 96500)`
`:. i_(0) xx t = 115800` coulomb
Now energy used `= Q xx V = 115800 xx 3 = 347.4 kJ`