What is a buffer solution?

A buffer solution is characterized by its ability to resist changes in pH when small amounts of an acid or a base are added. This property is crucial in many chemical and biological processes, as it helps maintain a stable environment in various systems, such as biological tissues and laboratory experiments.

Buffers typically consist of a weak acid and its conjugate base or a weak base and its conjugate acid. When an acid is added to a buffer, the weak base component reacts with the added hydrogen ions, minimizing the change in pH. Conversely, if a base is introduced, the weak acid component donates hydrogen ions to counteract the increase in pH.

The other options do not accurately define what a buffer solution is. A buffer does not completely neutralize acids, it does not inherently conduct electricity (though solutions containing ions do), and it fundamentally does not pertain to the rate at which it evaporates. The core characteristic of a buffer is its pH-stabilizing capability, which is what makes it essential for maintaining the desired conditions in various chemical environments.