Mg (s) + 2HCl (aq) → MgCl₂ (aq) + H₂ (g)ExplanationMg(s) is solid magnesium ribbon.HCl(aq) is hydrochloric acid in aqueous form.When they react, magnesium displaces hydrogen and forms magnesium chloride (MgCl₂) and hydrogen gas (H₂).This is a single displacement reaction, and you will see bubbles (effervescence) when the hydrogen gas is released.