溶液之ph值問題

In theory, at the end point, the pH is 7.

In fact, when use indicator to detect the end point, the end point will not be pH 7, for example, ammonia vs HCl , we use methyl orange as indicator, the colour change is at about pH 3.8. [pH 4.4 is yellow, pH3 is red]

當量點=equivalent point
Equivalent point != End point

其實當量點意思為 受滴定的溶液和滴定的溶液
剛剛好完全反應
所以上例pH一定為7


2008-10-24 22:14:15 補充：
「完全反應」既意思係兩種化合物跟據反應式既摩爾比例
剛剛好反應, 兩者沒有剩餘

你資料不足, 叫人點答?