Question

Ethanol and dimethyl ether form a pair of functional isomers. The boiling point of ethanol is higher than that of dimethyl ether due to the presence of

• A. H-bonding in ethanol
• B. H-bonding in dimethyl ether
• C. $-CH_3$ group in ethanol
• D. $-CH_3$ group in dimethyl ether

Answer 1

Answer: (A)

H-bonding in ethanol

Answer 2

Alcohols have higher boiling points as compared
to other organic compounds of similar molecular
masses such as ethers. This is due to the presence of
intermolecular hydrogen bonding in alcohols which
is absent in ethers. Because of hydrogen bonding in
alcohols, these exist as associated molecules rather
than discrete molecules. Consequently, a large
amount of energy is required to break these bonds
and therefore, their boiling points are high.