弱酸pH=1/2(pKa-logC)
1/2(4.2-log0.15)=Ans
log0.15=log(1/100)+log5+log3
=-2+(1-0.301)+0.4771
=-0.8239
78 已知苯甲酸(Benzoic acid)之pKa = 4.20,則0.15 ..-阿摩線上測驗