In what scenario would the pH at the equivalence point be lower than 7 during a titration?

The scenario where the pH at the equivalence point is lower than 7 occurs during the titration of a strong acid with a weak base. When a strong acid is titrated with a weak base, the strong acid fully dissociates in solution, producing a significant concentration of hydronium ions (H3O+).

At the equivalence point of this titration, all the weak base has reacted with the strong acid, resulting in the formation of a conjugate acid of the weak base. This conjugate acid can further donate protons to the solution, increasing the concentration of H3O+ ions. Consequently, this leads to a solution that has an acidic character, reflected in a pH value that is less than 7 at the equivalence point.

This behavior contrasts with titrations involving strong bases paired with strong acids, which typically have a neutral pH at equivalence, or weak acids with weak bases, which can yield a neutral or near-neutral pH depending on the strengths of the two substances involved. In the case of a weak base with a strong acid, it's important to recognize that the pH will drop below 7 due to the dominance of the strong acid and its ability to produce more