Almost all acid molecules contain one or more hydrogen atoms, which separates from the acid when it is mixed with a base.
Most acids have hydrogens, whereas many bases contain hydroxide subgroups. The hydrogen that separates from an acid often attaches to the hydroxide on the base. Hydrogen ions are also referred to as protons. Therefore, acids are sometimes referred to as proton donors. Similarly, bases are sometimes referred to as proton acceptors.
A reaction between an acid and a base is called a neutralization reaction. The general equation for a neutralization reaction is:
Acid + Base --> Salt + Water
The water is formed when the hydroxide ion(s) from the base (OH-) combines with the proton(s) (H+) of the acid. The salt is formed from the combination of the anion of the acid and cation of the base.