Fundamentals of Acids and Bases
A Bronsted acid is a (proton) + donor, whilst a Brønsted base is a proton acceptor. An acid-base reaction involves the exchange of a proton between a base and an acid. An acid reacts with water to produce the hydronium ion, a conjugate base, and H3O+. A base reacts with water to produce the OH-, hydroxide ion, and a conjugate acid.
A reaction between an acid and a base (an acid-base reaction) involves the exchange of a proton, for example:
These definitions apply under all conditions, but the most important acid-base systems use water as a solvent. In this case, equilibria are set up in water, which for HA (a general acid) is:
and for B (a general base) is: