What is the role of a buffer in a solution?

Buffers play a crucial role in maintaining the pH level of a solution. They are typically weak acids or bases that can neutralize small amounts of added acid or base without significantly altering the overall pH. This is essential in biological systems because many biochemical processes are highly sensitive to changes in pH. For instance, enzymes, which facilitate chemical reactions in the body, often work best within a narrow pH range.

When an acid or base is added to a buffered solution, the buffer reacts to minimize the change in pH. This stabilizing function helps to ensure that environments such as blood, cellular fluids, and other biological settings remain within the optimal pH range for the proper function of physiological processes.

The other options do not accurately describe the primary role of a buffer. Increasing the temperature does not relate to the function of a buffer, nor does promoting chemical reactions or dissolving solid materials. These processes may be influenced by pH but are not directly relevant to the buffering action itself.