Water can act as a base by accepting a proton in the reaction with hydrochloric acid.
Water (H₂O) can act as both an acid and a base in certain reactions. In the reaction between hydrochloric acid (HCI) and water (H₂O), water accepts a proton from the acid, making it a Brønsted-Lowry base.
This can be seen in the equation:
HCl(aq) + H₂O(aq) → H₃O⁺ (aq) + Cl¯ (aq)
This shows that water behaves as a base by accepting a proton to form hydronium ions (H₃O⁺).