What is the primary function of a buffer solution?

The primary function of a buffer solution is to maintain a constant pH when acids or bases are added. Buffers are typically composed of a weak acid and its conjugate base or a weak base and its conjugate acid. This composition allows them to react with added H⁺ or OH⁻ ions, minimizing changes in pH.

When an acid is introduced to the solution, the weak base component of the buffer can absorb the excess H⁺ ions, thereby preventing a significant decrease in pH. Conversely, if a base is added, the weak acid component can donate H⁺ ions to counteract the increase in pH. This stabilizing effect is crucial in many biological and chemical processes where a specific pH range is needed for optimal function, making buffers essential in various applications, including biological systems, industrial processes, and laboratory experiments.