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

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 κ_t. 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.

Key words: Physical chemistry experiment, Saponification reaction, Rate constant, Apparent activation energy, Pre-exponential factor