紫外-可见吸收光谱法测定配合显色反应的焓变

Determination of Enthalpy Change of Coordinating Color Reaction by UV Vis Absorption Spectrum Method

本文提出一种测定显色反应焓变的简单实验方法 ,推导出吸光度与温度的关系式 ,用Tween 80介质中的硫氰酸钴 (Ⅱ )配合物显色反应验证了关系式的线性关系 ,得到相关系数 r为 0 995 7,ΔH =- 44 7kJ·moL-1,同Van′tHoff方程得到的结果基本一致。

In this paper,a simple experimental method for the determination of enthalpy change of coordinating color reaction has been proposed and a relation formula between absorption and temperature has been deduced.Using coordinating color reaction of cobalt(Ⅱ) thiocyanate in Tween 80 medium,the linear relation of this formula has been validated:r=0 995 7 and Δ H=-44 7 kJ·mol -1 ,which is accordant with the result obtained from Van′t Hoff equation.