Why does aluminium react slowly with hydochloric acid?

Answer 1

Aluminium metal at first reacts a bit  slowly with dilute hydrochloric acid, reason for this slow reaction is that, aluminium metal holds a protective layer of aluminium oxide on its surface. But when the thin, outer oxide layer gets dissolved in acid,, then fresh aluminium metal is exposed which reacts rapidly with dilute hydrochloric acid. Thus,

Aluminium metal reacts rapidly wjth dilute hydrochloric "acid to form aluminium chloride and hydrogen gas :

The reaction of aluminium with dilute hydrochloric acid is- less rapid than that of magnesium, so aluminium is less reactive than magnesium.

Answer 2

because it does