The esterification reaction is a reversible reaction. In order to increase the yield of esters, the reaction must proceed as far as possible in favor of ester formation. Generally, one of the reactants acid and alcohol is excessive. In industrial production, which kind of excess is better depends on the specific conditions of whether the raw materials are readily available, whether the price is cheap, and whether it is easy to recycle. In the laboratory, the method of excessive ethanol is generally adopted. The mass fraction of ethanol should be high. It would be better if absolute ethanol could be used instead of 95% ethanol.
The amount of concentrated sulfuric acid used in the catalysis is very small. Generally, as long as the mass of sulfuric acid reaches 3% of the mass of ethanol, the catalytic effect can be completed. However, in order to remove the water generated in the reaction, the amount of concentrated sulfuric acid should be increased slightly. When preparing ethyl acetate, the reaction temperature should not be too high. When it is kept between 60°C and 70°C, impurities such as diethyl ether, sulfurous acid or ethylene will be generated when the temperature is too high. After the liquid is heated to boiling, it should be replaced with a small fire. A few pieces of broken porcelain can be added to the test tube in advance to prevent the liquid from boiling.