- For an individual weak acid or weak base component, see Buffering agent. For uses not related to acid-base chemistry, see Buffer (disambiguation).
A
buffer solution (more precisely,
pH buffer or
hydrogen ion buffer) is an
aqueous solution consisting of a
mixture of a
weak acid and its
conjugate base, or vice versa. Its pH changes very little when a small or moderate amount of
strong acid or
base is added to it and thus it is used to prevent changes in the pH of a solution. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. Many life forms thrive only in a relatively small pH range so they utilize a buffer solution to maintain a constant pH. In nature, the
bicarbonate buffering system is used to regulate the pH of
blood.
