Low molecular weight esters have fruity flavors and odors. Why do esters, which have higher molecular weights than carboxylic acids, have lower boiling points than the carboxylic acids they were made from?
a. Carboxylic acids are solids and harder to liquify than their esters.
b. Carboxylic acids have much stronger intermolecular Van der Waals forces.
c. Most carboxylic acids exist as dimers which are held together by two hydrogen bonds.
d. Ester molecules have strong hydrogen bonding forces with other ester molecules which helps increase their volatility.
e. Boiling points of all organic esters decrease with increasing molecular weight.
Answer: c. Most carboxylic acids exist as dimers which are held together by two hydrogen bonds.