Question

Which of the following compounds would have the lowest boiling point? A) 2-hydroxypropane B) 1-hydroxypropane C) ethoxyethane D) 1-hydroxyethane

Answer 1

Ans: ethoxyethane

Only ethoxyethane is an ether, other three are alcohols. Alcohol contains OH group and due to this bond there is a weak hydrogen bonding between the molecules of alcohols. So the molecules are held together and boiling point is increased. More energy is required to break the H-bonds and to vaporize the alcohol molecules.

Ether molecules do not contain -OH group. No intermolecular hydrogen bonding occurs between ether molecules.

Ethers therefore have quite low boiling points than alcohols.