What is the primary function of a buffer solution?

The primary function of a buffer solution is to resist changes in pH when small amounts of 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 the buffer to neutralize added acids (H⁺ ions) or bases (OH⁻ ions) effectively, maintaining the overall pH of the solution within a narrow range.

When an acid is introduced to a buffer solution, the weak base component of the buffer reacts with the added H⁺ ions, while the weak acid can dissociate to supply H⁺ ions if a base is added, thus minimizing any significant change in the solution's pH. This property makes buffers crucial in many biological and chemical processes where a stable pH is essential for optimal functioning.