(2) The basicity of an acid isthe number of hydrogen ions(H+) which can be produced bythe ionization of one moleculeof the acid in aqueous solution.For example, the basicity ofhydrochloric acid is 1 since onemolecule of HCl produces oneH+ ion in solution. Similarly,the basicity of Disodium phosphate(Na2HPO4)is one sinceit has one H+ displaceable ion.