Buffer solutions are solutions that resist changes in pH when small amounts of acid or base are added. They consist of a weak acid and its conjugate base (or a weak base and its conjugate acid) which act together to maintain the pH.
Related terms
Acidic Buffer: A buffer solution with a pH less than 7, containing a weak acid and its conjugate base.
Basic Buffer: A buffer solution with a pH greater than 7, containing a weak base and its conjugate acid.