The hydrogen on the hydrogen chloride donates its hydrogen proton to the water, resulting in a cation of H3O+ and an anion of Cl-. HCl + H2O = H3O+ + Cl-. In contrast to the acid definition, a Bronsted-Lowry base is a substance that accepts protons. An example of a proton acceptor is ammonia (NH3).
so ur answer is proton (H+) donor
