Question

Aluminium is extracted from its chief ore, bauxite. The ore is first purified and then the metal is extracted from it by electrolytic reduction.

Write an equation for the reaction which takes place at the anode during the extraction of aluminium by the electrolytic process.

Answer 1

At anode:

\[\ce{6O^{2-} - 12e^- -> 6[O]}\]

\[\ce{3[O] + 3[O] -> 3O2}\]

Anode is oxidised to carbon monoxide, which further forms carbon dioxide.

\[\ce{2C + O2 -> 2CO}\]

\[\ce{2CO + O2 -> 2CO2}\]