2H2O=H++OH- Kw=[H+][OH-]HAc=H++Ac- Ka=[H+][Ac-]/[HAc]Ac-+H2O=HAc+OH- Kb=[HAc][OH-]/[Ac-]=Kw/Ka=5.55*10^(-10)0.05-x x xKb=x²/(0.05-x²)=5.55*10^(-10)解得[OH-]=x=5.27*10^(-6)pOH=-lg[OH-]=-lg[5.27*10^(-6)]=5.28pH=14-pOH=14-5.28=8.72