关键词: 乙酸乙酯, 可视化, 甲基紫, 制备

Abstract:

In order to introduce the concept of visualized experiment into basic laboratory teaching and to enhance the exercise on esterification, comprehensive improvement was made on the preparation of ethyl acetate. In this experiment, acetic acid reacts with ethanol to produce ethyl acetate in the presence of sodium bisulfate and allochroic silica gel, and the endpoint of the reaction is vidually indicated by methyl violet discoloration. This design of the reaction circumvents the problems of limited reagents and carbonization. The conversion was measured by gas chromatography, and the result showed that acetic acid was almost completely turned into the target product; the structure of the product was confirmed by ¹H NMR. This experiment allows students to have a feel of the dynamic process of esterification by the discoloration of methyl violet with the increased acidity of the reaction system. Consequently, it can enhance students' interests in learning organic chemistry, enliven their thinking and improve their study efficiency.

Key words: Ethyl acetate, Visualization, Methyl violet, Synthesis