相对滴定法

THE STUDY OF THE FUNDAMENTAL OF RELATIVE TITRATION

以物料平衡、电荷平衡和化学平衡为基础，通过严格的数学推导提出一种新的滴定分析理论──相对滴定法．它是以相同滴定状态下（如ｐＨ、ｐＭ、电位、吸光度等）被测物质的量与滴定剂体积之间的线性关系为基础，通过仪器分析方法（如标准曲线法、标准加入法等）进行定量计算．该法在滴定过程中的任一状态都成立，不需确定等当点，从根本上消除了终点误差，不仅适用于滴定突跃很小的体系，还适用于滴定反应未知的滴定过程．本文以强碱滴定一元弱酸为例，通过系统的误差分析，确定了影响相对滴定法精度、灵敏度的因素及选择最佳实验条件的方法，并通过强碱对硼酸的滴定进行验证，结果与理论分析完全吻合．

elative titration method is a new analytical theory based on strict mathematical treatments to the equations of mass balance, charge balance and chemical equilibrium. The relative titration method can be applied not only to the systems which have small equivalent point breaks but also the systems in which the chemical reactions are not ascertained during the titration. In this article, the factors which affect the precision and sensitivity of the relative titration and the principle of selecting optimum experiment conditions are determined by theoretical analysis of errors in the system of monoprotic weak acid titrated by strong base. The theoretical conclusions are compatible with the experimental results in the titration of H3BO3 by NaOH.