根据缓冲溶液PH计算公式PH=PKa-Log(C酸/C盐)PKa=8-0.79=7.21,混合后C酸=0.1x0.1/(0.1+0.05)=1/15;C盐=0.2x0.05/(0.1+0.05)=1/15PH=7.21-Log1=7.21