What are amphoteric oxides? Give two examples of amphoteric oxides.

Explanation

These are the oxides which can act both as acids and bases. For example, aluminium oxide `(Al_(2)O_(3))` and zinc oxide (ZnO). The amphoteric character of the two oxides are shown by the following reactions.
`underset(("Basic nature"))(Al_(2)O_(3)(s))+6HCl(aq) rarr underset("Aluminium chloride ")(2AlCl_(3)(aq)+3H_(2)O(aq))`
`underset(("Acidic nature"))(Al_(2)O_(3)(s)) + 2NaOH (aq) rarr underset("Sodium meta-aluminate ")(2NaAlO_(2)(aq) + H_(2)O(aq))`
`underset(("Basic nature"))(ZnO(s))+ 2HCl(aq) rarr underset("Zinc chloride")(ZnCl_(2)(aq))+H_(2)O(aq)`
`underset(("Acidic nature"))(ZnO(s)) + 2NaOH(aq) rarr underset("Sod. zincate")(Na_(2)ZnO_(2)(aq)) + H_(2)O(aq)`