Suggest reasons for this observation and explain your reasoning: Since esters are cleaved on hydrolysis, the molecular weight of the acid derived from an ester is always lower than the molecular weight of the ester. However esters are usually liquids while carboxylic acids are usually solids.

Question

Suggest reasons for this observation and explain your reasoning: Since esters are cleaved on hydrolysis, the molecular weight of the acid derived from an ester is always lower than the molecular weight of the ester.  However esters are usually liquids while carboxylic acids are usually solids.

aaronq · Answer

well, since you're hydrolyzing the ester you're breaking it apart, do the resulting pieces are gonna be smaller than the parent. Just as if you snapped a tree branch in two, the resulting pieces will be smaller than the initial.

The second part has to do with intermolecular forces, carboxylic acids are able to hydrogen bond and thus have stronger attractions, while esters' strongest IMF is dipole-dipole attractions.