Question

In order to obtain one tone of aluminium, the following inputs are required:
4 tones of bauxite, 150 Kg of sodium hydroxide and 600 Kg of graphite.
The aluminium compound in bauxite is aluminium oxide and the main impurity is iron (II) oxide. Aluminium is obtained by the electrolysis of aluminium oxide dissolved in cryolite.
(i) Name the process used for purification of bauxite.
(ii) Write the equation to show the action of heat on aluminium hydroxide.

Answer 1

(i) Baeyer's process or Hall's process is used for the purification of bauxite.
(ii ) \[\ce{2Al(OH)3 + Heat -> Al2O3 + 3H2O}\]