Question

Would you expect the equivalence point ph of the wasb to be slightly acidic, neutral, or slightly basic? how does this compare to the sasb equivalence point ph?.

Answer 1

The equivalence point pH in a weak acid-strong base titration (WASB) is expected to be slightly basic, contrasting with the neutral pH at the equivalence point in a strong acid-strong base titration (SASB).

Step-by-step explanation:

When titrating a weak acid with a strong base, the equivalence point pH is expected to be slightly basic because the conjugate base of the weak acid will react with water to produce hydroxide ions (OH-), which makes the solution basic. In contrast, the equivalence point pH of a strong acid-strong base titration (SASB) is neutral, at a pH of 7, as the strong acid completely reacts with the strong base, resulting in a neutral salt and water without any significant amounts of excess hydroxide or hydronium ions.

For example, in the titration of hydrochloric acid (a strong acid) with sodium hydroxide (a strong base), the equivalence point occurs at a pH of 7.00. This is different from a weak acid-strong base titration (WASB), where the equivalence point's pH is significantly greater than 7 due to the presence of the conjugate base which is weakly basic. Beyond the equivalence point, additional strong base will increase the pH further, similarly in both SASB and WASB titrations. However, the pH increase in SASB postequivalence is due to the presence of excess strong base, while in WASB, it is also influenced by the weakly basic nature of the conjugate base.