Do not extend the airway tube into the Na2CO3 solution to prevent the uneven heating of the Na2CO3 solution into the test tube heating the reactants. Moreover, ethanol and acetic acid are very soluble in water, which can cause reverse absorption. Concentrated sulfuric acid acts as both a catalyst and a water-absorbing agent. The role of Na2CO3 solution is:
(1) The role of saturated sodium carbonate solution is to condense the ester vapor, reduce the solubility of the ester in water (facilitate the separation), remove the acetic acid mixed in ethyl acetate, and dissolve the ethanol mixed in ethyl acetate.
⑵ Na2CO3 can react with volatile acetic acid to form odorless sodium acetate, which is convenient for smelling ethyl acetate.