极弱酸碱的直接电位滴定  

DIRECT POTENTIOMETRIC TITRATION OF VERY WEAK ACID AND VERY WEAK BASE

作　　者：冯俊贤[1] 王秀卿[1] 郄文娟[1] 李素娟[1] 

机构地区：[1]解放军白求恩军医学院,石家庄050081

出　　处：《理化检验（化学分册）》2004年第2期77-79,共3页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

摘　　要：讨论了用两点电位滴定法直接测定pKa(或pKb)在10左右的极弱酸碱的可行性。该法只需在计量点后适当位置测定两组滴定数据,即可确定滴定计量点。与线性电位滴定法比较,两者结果一致。The feasibility of application of the two-point potentiometry to the titration of very weak acids and very weak bases, having their values of pK_a (or pK_b) around 10, was discussed. By the two-point potentiometric method only two sets of data (including the volume of titrant consumed, its corresponding pH value and potential at each point) after and near the estimated stoichiometric point were taken, and the exact stoichiometric point was calculated upon these data by the formula given in this paper. In a comparative study of the proposed method with the linear potentiometric method, no significant difference was found between them. But the two-point potentiometric method was much simple and easy to manipulate.

关 键 词：弱酸 弱碱 直接测定 两点电位滴定法 滴定计量点 线性电位滴定法 

分 类 号：O657.1[理学—分析化学]