Question

Can you explain me what is Basicity of acids and Acidity of bases.

Answer 1

basicity of acids : the number of hydrogen ions[H+], that can be produced per molecule of the acid in aqueous solution, or the number of hydroxyl ions with with one molecule of an acid combines
eg: H3PO4, or phosphoric acid can produce 3 hydrogen ion in aq. soln., each ion combines with one hydroxyl ion, hence it's basicity is 3

acidity of bases : the number of hydroxyl ions[OH-] , that can be produced per molecule of the base in aq. soln., or the number of hydrogen ions with with one molecule of a base combines
eg: Ca(OH)2 , or calcium hydroxide or "slake lime" , can produce 2 hydroxyl ions in aqueous solution, which can combine with two hydrogen ion(each hydroxyl ion combines with one hydrogen ion, to form one molecule of water during a neutralization reaction), hence it's acidity is 2.