Question

how to test aluminium has amphoteric nature?​

Answer 1

Amphoteric nature means showing both acidic and basic nature.

Acidic nature( Reaction with alkalis)

2Al (s) + 2NaOH(aq) + 6H2O(l) 2 Na+ [Al(OH)4] –(aq) + 3H2(g)

Sodium

tetrahydroxoaluminate(III)

Basic nature(Reaction with acids)

2Al(s) + 6HCl (aq) → 2Al3+ (aq) + 6Cl– (aq) + 3H2 (g)

Answer 2

Hey friend, To test that Aluminium has amphoteric nature, you should Take a Aluminium foil or Any sheet of element.....

Leave it for sometime,then as the oxygen layer is formed......i.e. Oxide of ALUMINIUM ELEMENT then, test it with acids and bases.....

As you will observe that water and Aluminium salt .....is formed.......in both the cases,,,with acids and bases.....

Ex: Al2O3 + 6HCL -2AL(CL)3+ 3H2O........

THAT IS A REACTION OF ALUMINIUM OXIDE WITH HYDROCHLORIC ACID TO FORM ALUMINIUM CHLORIDE AND WATER.....

Now, reaction of Aluminium oxide with a base.....

AL2O3 + 2NaOH----- 2NaAL(O2) + H2O...

That is a reaction of aluminium oxide with a base..... I. e. Sodium hydroxide to form Sodium Aluminate and water.......