根据离子积常数的转换,即
c(H+) * c(OH-) = Kw
上式左右两边,同时取负对数,得
PH + POH = 14
POH = -lg[c(OH-)]
PH = -lg[c(H+)]
备注：离子积常数随温度升高而升高,25摄氏度时为Kw =10^-14,100摄氏度时Kw =10^-12