氧化还原滴定方法理论新说  

New Theory for Principle of Redox Titration

作　　者：岳宣峰[1] 秦丹 张可欣 刘阳禾 王梁宇 张婷 张延妮[2] Xuanfeng Yue;Dan Qin;Kexin Zhang;Yanghe Liu;Liangyu Wang;Ting Zhang;Yanni Zhang(Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province,School of Chemistry and Chemical Engineering,Shaanxi Normal University,Xi’an 710062,China;Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry,Shaanxi Normal University,Xi’an 710062,China)

机构地区：[1]陕西师范大学化学化工学院,陕西省生命分析化学重点实验室,西安710062 [2]陕西师范大学药用资源与天然药物化学教育部重点实验室,西安710062

出　　处：《大学化学》2023年第8期283-292,共10页University Chemistry

基　　金：陕西省自然科学基础研究计划(2022JZ-54);陕西师范大学教学改革研究项目(22JG35);陕西师范大学大学生创新训练项目(202210718054,CY2022018)。

摘　　要：为了改造氧化还原滴定分析方法的标度,从而逐步建立统一的滴定分析标度计算式,提出了相对电子浓度Re-的概念,基于此发展了以p R_(e-)为监测标度的氧化还原滴定方法新理论。该理论描述了氧化还原半反应的平衡,推导了氧化还原滴定标度p Re-的计算通式,探索了该标度在滴定过程中的一般变化规律,重新梳理了指示剂的指示原理。以Ce^(4+)滴定Fe^(3+)溶液为例,演绎了如何简单绘制滴定曲线、计算滴定突跃范围、判断可否直接准确滴定,讨论了氧化还原反应条件平衡常数K_(τ)^(θ’)的大小对滴定分析的影响。To transform the scale of redox titration for a unified formula of the titration scale,a relative concentration of the aqueous electron Re-is proposed,and a new theory for redox titration is then developed with pRe-as its monitoring scale.This new theory addresses the balancing of the semi-redox-reaction,provides the general formula for calculating pR_(e-),investigates the general variation of pRe-in titration,and reintroduces the principle of an electron indicator.In this study,the titration of Ce^(4+t)o Fe_(3+)solution is used as an example to deduce the following aspects:the approach for drawing titration curves,calculation for titration jump ranges,and criterion of direct and accurate titrations.Finally,the effect of K_(τ)^(θ’),which is the conditional equilibrium constant of a redox reaction,on titrimetric analysis is discussed.

关 键 词：氧化还原滴定 相对电子浓度 滴定曲线 电子指示剂 准确滴定 

分 类 号：G64[文化科学—高等教育学] O651[文化科学—教育学]