在化学计量点时,溶液中HAc与NaOH全部反应生成NaAc,此时体积增大一倍,所以NaAc的浓度为0.05 mol/L.
[OH-] = √Kw / Ka * c
=√ (10^-14) / (1.8*10^-5) * 0.05
=5.3*10^-6 (mol/L)
PH = 14 - POH = 14 - 5.28 = 8.72