How do you determine pH at an equivalence point?
When all of a weak acid has been neutralized by strong base, the solution is essentially equivalent to a solution of the conjugate base of the weak acid.
For example, if a 0.2 M solution of acetic acid is titrated to the equivalence point by adding an equal volume of 0.2 M NaOH, the resulting solution is exactly the same as if you had prepared a 0.1 M solution of sodium acetate.
The pH of 0.1 M sodium acetate is calculated as follows:
pOH = -log(
pH = 14 - pOH = 8.87