Puhverdusvõime

Puhverdusvõime, often translated as buffering capacity, refers to the ability of a system, typically a solution, to resist changes in pH when small amounts of an acid or a base are added. This resistance is a crucial property in many chemical and biological processes. A system with high puhverdusvõime can absorb a significant amount of added acid or base without a substantial alteration of its pH.

The effectiveness of a buffer system is determined by the concentrations of its components. Typically, a buffer consists of a weak acid and its conjugate base, or a weak base and its conjugate acid. The pH at which a buffer is most effective is close to the pKa of the weak acid (or pKb of the weak base). When the concentrations of the weak acid and its conjugate base are equal, the buffer exhibits maximum buffering capacity.

Puhverdusvõime is particularly important in biological systems, where maintaining a stable pH is essential for enzyme activity and cellular function. For instance, the human blood has a sophisticated buffering system involving bicarbonate, phosphate, and proteins that keeps the blood pH within a narrow range, despite the metabolic production of acids. In chemistry, buffers are used in titrations, chemical reactions, and analytical procedures to control pH. The quantitative measure of buffering capacity is often expressed as the amount of acid or base needed to change the pH of one liter of the buffer solution by one unit.