What are buffers primarily made up of?

Buffers are primarily composed of a weak acid and its conjugate base. This combination is crucial because it allows the buffer system to maintain a relatively stable pH when small amounts of strong acids or bases are added to the solution. The weak acid can donate protons (H⁺) when there is an increase in pH (addition of a base), and its conjugate base can accept protons when there’s a decrease in pH (addition of an acid). This equilibrium between the weak acid and conjugate base is what enables the buffer to resist changes in pH, making them extremely important in biological systems where pH stability is essential for proper functioning.

In contrast, a strong acid and its conjugate base would not work effectively as a buffer because strong acids completely dissociate in solution, leading to rapid changes in pH. Similarly, focusing solely on salts or strong bases would not provide the necessary mechanism for pH stabilization. Therefore, the presence of both a weak acid and its conjugate base is key to the buffering action.