A strong acid completely dissociates into its ions in aqueous solution. Hydrochloric acid is an example of a strong acid.HCl(aq) → H+(aq) + Cl-(aq)A weak acid only partially dissociates in aqueous solution. Ethanoic acid is a weak acid.CH3COOH (aq) ⇌ CH3COO-(aq) + H+(aq)Note the use of → for a strong acid and ⇌ for a weak acid.