What is a buffer solution and how does it resist changes in pH?

A buffer solution is a solution that resists changes in pH.

Buffer solutions are important in biological systems as they help to maintain a stable pH, which is necessary for many biochemical reactions to occur. A buffer solution is made up of a weak acid and its corresponding conjugate base, or a weak base and its corresponding conjugate acid. When an acid or base is added to a buffer solution, the buffer components react with it to prevent a large change in pH.

The resistance of a buffer solution to changes in pH is due to the equilibrium that exists between the weak acid and its conjugate base. When an acid is added to the buffer solution, the weak base component of the buffer reacts with the acid to form more of the weak acid component. This reaction removes some of the added acid, preventing a large change in pH. Similarly, when a base is added to the buffer solution, the weak acid component of the buffer reacts with the base to form more of the weak base component. This reaction removes some of the added base, preventing a large change in pH.

Buffer solutions are used in many biological processes, such as in the blood where they help to maintain a stable pH despite changes in metabolic activity. They are also used in laboratory settings to maintain a constant pH during experiments.