Base

Base, a chemical substance which has the power of reacting with an acid (q.v.) to form a compound differing in properties from both the acid and the base, called a salt (q.v.). Bases may be (1) metallic oxides, such as sodic oxide, copper oxide CuO, etc.; (2) metallic hydroxides, i.e. compounds of a metal with hydrogen and oxygen, as sodium hydrate NaOH, etc.; or (3) ammonia and certain allied compounds. Many organic substances (Alkaloid) also exhibit basic properties. In the interaction of a base and acid water may or may not be formed.

Bases are defined as mon-acid, di-acid, etc., according to the number of hydrogen atoms of the acid, Which are displaced in the reaction with one molecule of the base. Thus the copper oxide is di-acid, the sodium hydroxide mon-acid.