Weak Acid - Strong Base
Must take into account the weak acid / conjugate base equilibrium.
At the equivalence point, we have a solution of the conjugate base.
50.0 mL 0.100 M CH3CO2H + 50.0 mL 0.100 M NaOH ? 100.0 mL 0.0500 M CH3CO2-
Calculate pH as for weak base: pH = 8.728
Note narrower range of pH change (6-11); phenolphthalein okay here, but might need a different indicator for a different weak acid.