Which statement best describes the composition of a buffer solution?

A buffer solution is defined as a system that can resist changes in pH upon the addition of small amounts of acid or base. The key to its efficacy lies in its composition. A typical buffer consists of a weak acid and its conjugate base or a weak base and its conjugate acid. This combination allows the buffer to neutralize added acids (which can donate protons) or bases (which can accept protons), thereby stabilizing the pH of the solution.

For example, in a buffer made from acetic acid (a weak acid) and sodium acetate (the conjugate base), if an acidic substance is added, the acetate ions can react with the additional protons to minimize the change in pH; conversely, if a base is added, the acetic acid can donate protons to reduce the impact of that base. This interplay between the weak acid and its conjugate base is what defines the functionality of a buffer solution.

In contrast, compositions that consist only of strong acids or salts do not provide this level of pH stabilization, as strong acids completely dissociate in solution and do not have a conjugate base to mitigate pH changes. Thus, a well-constructed buffer system containing a weak acid and its