Chemistry Regents Practice Test 2026 – The All-in-One Guide to Exam Success!

A buffer solution is designed to maintain a relatively constant pH when small amounts of an acid or a base are added. The primary component of a buffer consists of a weak acid and its conjugate base. This combination allows the solution to resist changes in pH, as the weak acid can donate protons (H+) to neutralize added bases, while the conjugate base can accept protons to neutralize added acids.

When a small amount of acid is introduced into the buffer solution, the weak acid component can react to mitigate the increase in H+ concentration, thus resisting a significant change in pH. Conversely, if a base is added, the conjugate base component can react with incoming H+ ions, helping to keep the pH stable. This dual action of the weak acid and its conjugate base is what makes buffers effective in a wide variety of chemical and biological applications, such as regulating the pH in living organisms.

In contrast, the other options do not exhibit the same buffering capacity. Strong acids and their conjugate bases or strong bases and their conjugate acids do not provide the same ability to resist changes in pH because strong acids and bases fully dissociate in solution, leading to more dramatic shifts in pH rather than