摘要
用电化学方法测量了二元溶液体系的混合熵。将亚铁氰化钾溶液与铁氰化钾溶液混合成一系列“反比溶液”,每对反比溶液可以组成一个浓差电池,并测量其电动势。溶液混合过程的总电功可以通过可逆电动势Erev与溶液组成x关系曲线计算,从而得到混合吉布斯自由能ΔmixG。根据理想溶液体系ΔmixG=TΔmixS的性质,进而推算溶液的混合熵ΔmixS。实验设计用于验证理想溶液的热力学性质,增强学生学习物理化学课程的真实感。
The entropy of mixing for a binary solution system is determined from electrochemical measurements.The solution of K_(4)Fe(CN)_(6) is mixed with the solution of K_(3)Fe(CN)_(6) to form a series of“inverse solutions”.Each pair of the inverse solutions can be used to construct a concentration cell system,and the electromotive force of the cell is measured.The total electrical work of the mixing process can be calculated from Erev~x curve and the Gibbs free energy of mixing(i.e.,ΔmixG)can be obtained.For ideal solution system,ΔmixG=TΔmixS.Therefore,the entropy of mixing,ΔmixS,is given.The experiment is designed to demonstrate the thermodynamic properties of ideal solutions,and add some reality to the students physical chemistry course.
作者
吴梅芬
王晓岗
许新华
WU Meifen;WANG Xiaogang;XU Xinhua(School of Chemical Science and Engineering,Tongji University,Shanghai 200092,China)
出处
《实验室科学》
2021年第3期9-13,17,共6页
Laboratory Science
基金
同济大学实验教改项目(项目编号:1380104103)。
关键词
混合熵
电化学测量
理想溶液
entropy of mixing
electrochemical measurement
ideal solution
