Along which of the following parts of a pHpH titration curve for a weak monoprotic acid/strong base is the solution buffered?

In a pH titration curve for a weak monoprotic acid titrated with a strong base, the solution exhibits buffering behavior primarily in two key areas:

1. Before the equivalence point: In this region, the weak acid is present alongside its conjugate base. The solution can resist changes in pH due to the presence of both species that can react with added acid or base.

2. At the equivalence point: Although initially, one might think the equivalence point represents a state where there is no buffering (as all weak acid has reacted with the strong base), the solution can still demonstrate buffering capacity due to the presence of the conjugate base formed during the reaction. Even though a significant change in pH occurs, the presence of the conjugate base helps to moderate pH changes.

Outside of these regions, particularly within the steep rise after the equivalence point, the solution lacks significant buffering capacity as the strong base predominates.

In summary, the solution is buffered primarily:

• Before the equivalence point
• At the equivalence point

This illustrates the importance of understanding areas of a titration curve in relation to buffering capacity.