示波电导滴定

Oscillographic Conductometric Titration

通常的电导滴定用电导仪测量滴定过程中溶液电导率的变化;以电导值对滴定剂体积作图,将两条直线外推,其交点为等当点。本文提出的示波电导滴定法,利用示波图的突然收缩或扩张指示滴定终点,简便快速,终点直观,适用于各类滴定反应。 1 原理 当交流电源输出电压为V=V_0sinωt,交流电频率较高,溶液浓度较稀时,“E～t”曲线与“i～t”曲线的相位差接近0°,电解池的阻抗接近纯电阻。若溶液电阻为R_L、外加电阻为R_0。

A cathode-ray oscillograph is directly connected to the electrodes of a conductometric titra-tion cell and the sudden change of the oscillogram is used to indicate the end-point of conductometric titration. The new technique has advantages over the usual conductometric titration methed: (1) The end-point can directly be perceived through the senses, and the graphic method for end-point location is no longer used. (2) The equipment and manipulation are more simple.