乙酸乙酯皂化反应速率常数的测定实验改进和拓展
Improvement and Expansion of the Experiment for Determining the Rate Constant of the Saponification Reaction of Ethyl Acetate
祝淑颖 1吴舒婷 1郑欧1
作者信息
摘要
本文针对现有物理化学实验教材中的"乙酸乙酯皂化反应速率常数的测定"实验进行改进和拓展.首先,以夹套烧杯为皂化反应池,通过恒温水循环及磁力搅拌确保了实验过程中溶液浓度均匀、温度恒定;其次,取一定体积浓度为0.01 mol∙L-1的氢氧化钠溶液于反应池中待恒温后测定电导率值,记为κ0,再使用微量取样器取等摩尔数的乙酸乙酯加入到反应器中并同时计时,测定不同时间的电导率值,记为κt;第三,通过数据归一化处理消除了电极常数的影响,使物理量意义明确、实验现象直观.改进后的实验步骤减少、数据测量准确性提高,可以测量高温条件下、快速的皂化反应速率常数,在有限的课时内学生可以通过分工协作、共享数据,获得表观活化能及指前因子.
Abstract
This paper focuses on the improvement and expansion of the experiment"Determination of the Rate Constant of Ethyl Acetate Saponification Reaction"in existing Physical Chemistry Experiment textbooks.Firstly,the saponification reaction vessel is replaced with a jacket beaker to ensure the uniform concentration and constant temperature of the solution during the experiment through constant temperature water circulation and magnetic stirring.Secondly,a certain volume of 0.01 mol·L-1 sodium hydroxide solution is taken and the conductivity value is measured after reaching a constant temperature,denoted as κ0.Then,an equal molar amount of ethyl acetate is added to the reactor using a micro sampler while simultaneously recording the conductivity values at different times,denoted as κt.Thirdly,the influence of electrode constant is eliminated through data normalization,providing clear physical quantities and intuitive experimental phenomena.The improved experimental procedure reduces steps and improves the accuracy of data measurement,allowing for the measurement of the rate constant of rapid saponification reactions under high temperature conditions.Within limited class time,students can obtain the apparent activation energy and pre-exponential factor through division of labor,collaboration,and data sharing.
关键词
物理化学实验/皂化反应/速率常数/表观活化能/指前因子Key words
Physical chemistry experiment/Saponification reaction/Rate constant/Apparent activation energy/Pre-exponential factor引用本文复制引用
基金项目
福建省本科高等学校教育教学研究项目(2022)(FBJG20220268)
出版年
2024
国家科技期刊平台
NSTL
万方数据