Final answer:
The pH at the equivalence point of the titration between CCL₃COOH and NaOH is calculated using the pKa of the weak acid and the Henderson-Hasselbalch equation, resulting in a pH greater than 7 due to the basic nature of the trichloroacetate ion.
Step-by-step explanation:
To calculate the pH at the equivalence point of a titration involving the weak acid trichloroacetic acid (CCL₃COOH) with a strong base (NaOH), you must consider the properties of the resultant anion, which in this case is the trichloroacetate ion (CCL₃COO-). As CCL₃COOH is a weak acid, it does not dissociate completely in water, but its conjugate base, the trichloroacetate ion, will partially react with water in a hydrolysis reaction to produce hydroxide ions (OH-) and weak acid (CCL₃COOH).
At the equivalence point, the moles of CCL₃COOH originally present will be equal to the moles of NaOH added, and all the CCL₃COOH will be converted into CCL₃COO-. You would use the provided pKa value to determine the pKb of the conjugate base and then apply the Henderson-Hasselbalch equation to calculate the pH. The pH at the equivalence point will be greater than 7 because the resulting solution is slightly basic due to the hydrolysis of the conjugate base.