化学计量点前0.1%:组成为Ac-、HAc。pH = pKa + lg([Ac-]/[HAc]) = 7.74。化学计量点后0.1%:组成为Ac-、OH-。PCE:[OH-] = c(NaOH) + [HA],解得 pH = 9.70。所以突跃为7.74~9.70。