Why is saturated sodium carbonate solution used when preparing ethyl acetate, and what happens if it is unsaturated?

Why is saturated sodium carbonate solution used when preparing ethyl acetate, and what happens if it is unsaturated?
The saturated sodium carbonate solution serves three critical functions in ethyl acetate production: it reduces the ester's solubility to facilitate phase separation, neutralizes unreacted acetic acid, and partially removes unreacted ethanol. When the solution is unsaturated, these effects weaken considerably. The carbonate reacts with carboxylic acids to form salts, increasing their solubility while decreasing ester solubility, which is essential for clean layering. In practice, insufficient saturation means incomplete acid removal and poorer separation, leaving impurities that compromise product quality. This is particularly relevant for industrial operations where consistent purity matters. The chemistry underscores why process control around the washing step directly impacts downstream solvent quality and yield recovery.