Question

“Aluminium oxide is an amphoteric oxide.” Justify this statement, giving chemical equations for the reactions involved.

Answer 1

Aluminium oxide is an amphoteric oxide due to its ability to react with both acids and bases, acting as a base with acids and an acid with bases, resulting in the formation of salt and water.

\[\ce{\underset{Base}{Al2O3} + \underset{Acid}{6HCl} -> \underset{chloride}{\underset{Aluminium}{2AlCl3}} + 3H2O}\]

\[\ce{\underset{Acid}{Al2O3} + \underset{Base}{2NaOH} -> \underset{Aluminate}{\underset{Sodium}{2NaAlO2}} + H2O}\]