Properties of Buffers

Properties of Buffers

• Buffers are aqueous systems that resist changes in pH when small amounts of an acid (H+) or a base (OH-) are added, or when the system is diluated.
• Buffers are composed of a weak acid and its conjugate base or a weak base and its conjugate acid.
• The pH of a buffer, determined by the ratio of the concentration of the weak acid to its conjugate base, or the weak base to its conjugate acid, remains nearly constant.
• Buffers are most effective when the pH is within 1 pH unit of the pKa (for acid buffers) or within 1 pH unit of the pKb (for basic buffers).
• In a buffered solution, addition of small amounts of an acid or a base doesn’t significantly change the pH of the solution.

Buffer’s Real-life Applications

• Physiological buffers maintain the pH of bodily fluids within narrow limits, which is crucial for the efficient functioning of metabolic processes.
• Buffers are used in many laboratory procedures and industrial processes to control pH, which can affect reaction rates, product yields and the formation of by-products.
• The carbonate system in oceans acts as a buffer to moderate changes in seawater pH.

Factors Affecting the Efficiency of Buffers

• Buffers lose their effectiveness when the concentration of the weak acid and its conjugate base (or the weak base and its conjugate acid) become too different.
• The capacity of a buffer – the amount of acid or base a buffer can neutralize – is largely dependent on the concentrations of its components.
• Temperature can affect buffer efficiency as it can change the equilibrium constants of the weak acid/base systems.

Remember: An understanding of buffers is essential in many areas of chemistry, from biological systems to industry. It allows you to predict how a system will respond to changes in conditions and thus is a key tool in controlling chemical reactions.