On the basis of the information available from the reaction : \[\frac{4}{3}Al+{{O}_{2}}\to \frac{2}{3}A{{l}_{2}}{{O}_{3}},\Delta G=-827KJ\,mo{{l}^{-1}}\] of \[{{O}_{2}}\], the minimum e.m.f. required to carry out electrolysis of \[A{{l}_{2}}{{O}_{3}}\] is \[(F=96500\,Cmo{{l}^{-1}})\]