Question

Calculate the quantity of electricity that would be required to reduce 12.3 g of nitrobenzene to aniline, if the current efficiency is 50%.

Answer 1

Reduction of nitrobenzene (C₆H₅NO₂) to aniline (C₆H₅NH₂) requires 6 electrons per molecule:

\[\ce{C6H5NO2 + 6 e- + 6 H+ -> C6H5NH2 + 2H2O}\]

Molar mass of C₆H₅NO₂ = 123 g/mol

Moles = `12.3/123` = 0.1 mol

Electrons required = 0.1 mol × 6 mol e⁻

= 0.6 mol e⁻

`Q_"actual"` = 0.6 × 96500 = 57900 C

Since current efficiency = 50%, the actual electricity needed is

`Q_"supplied" = 57900/0.50` = 115800 C