What is the function of a buffer solution?

A buffer solution plays a critical role in maintaining a stable pH in a given environment. Its primary function is to resist changes in pH upon the addition of small amounts of acids or bases. This capability is essential in many biological and chemical processes where extreme fluctuations in pH could disrupt reactions or affect the viability of organisms.

Buffers typically consist of a weak acid and its conjugate base or a weak base and its conjugate acid. When an acid or base is added to the solution, the buffer components react to minimize the pH change. For example, if an acid is added, the conjugate base present in the buffer will react with the hydrogen ions from the acid, effectively neutralizing them and thus stabilizing the pH.

This unique ability to "absorb" small amounts of acids or bases without significant pH changes is what makes buffers indispensable in laboratory conditions and physiological systems, such as human blood, where pH must remain within very narrow limits for optimal function.