Chemistry – Metals - Reactivity series | e-Consult

(a) The order of reactivity is: HCl > H₂SO₄ > HNO₃. Magnesium reacts fastest with dilute hydrochloric acid, followed by dilute sulphuric acid, and slowest with dilute nitric acid.

(b) The reaction rate is influenced by both the reactivity of the metal and the strength of the acid. Stronger acids generally react faster with metals. Dilute nitric acid is a weaker acid than dilute hydrochloric acid and dilute sulphuric acid. Therefore, the slower reaction with nitric acid is due to the weaker acid, even though magnesium is relatively reactive.