Question

CH₃CH₂OH boils at 78 C and CH₃OCH₃ boils at -24 C, although both compounds have the same composition. This difference in boiling points may be attributed to a difference in

a. molecular mass.
b. heat of combustion.
c. density.
d. covalent bonding.
e. hydrogen bonding

Answer 1

The difference in boiling points between CH₃CH₂OH and CH₃OCH₃ can be attributed to the presence of hydrogen bonding in ethanol.

Step-by-step explanation:

The difference in boiling points between CH₃CH₂OH (ethanol) and CH₃OCH₃ (dimethylether) can be attributed to the presence of hydrogen bonding in ethanol.

Hydrogen bonding is a strong intermolecular force that occurs when a hydrogen atom is bonded to a highly electronegative atom such as oxygen. In ethanol, the -OH group can form hydrogen bonds with other ethanol molecules, resulting in stronger intermolecular forces and a higher boiling point.

On the other hand, dimethylether does not have hydrogen bonding because it lacks a hydrogen atom bonded to an electronegative atom. It can only experience weaker dispersion forces, resulting in a lower boiling point.