When aluminium foil reacts with sodium hydroxide, sodium aluminate is formed. Metals react with dilute acids to form metallic salts and hydrogen gas. For example, Aluminium foil reacts with dilute hydrochloric acid to produce aluminium chloride and hydrogen gas.

The balanced chemical equation for the reaction is:

2Al(s) + 6HCl(aq) 2AlCl3(aq) + 3H2(g).

Aluminium is an amphoteric metal. It reacts with both acids and bases. The reaction is highly exothermic and produces a lot of heat. There is rapid evolution of hydrogen gas during this reaction.