Chemistry - Halogen Derivative Question with Solution | TestHub

For alkyl halides containing the same alkyl group, the boiling point increases with an increase in the atomic mass and size of the halogen atom.

As the size and mass of the halogen atom increase, the magnitude of van der Waals forces of attraction increases, which leads to a higher boiling point.

The order of atomic mass and size of halogens is $\text{F}<\text{Cl}<\text{Br}<\text{I}$.

Therefore, the boiling points of methyl halides follow the order: Fluoromethane $<$ Chloromethane $<$ Bromomethane $<$ Iodomethane.

Fluoromethane has the lowest boiling point.

Answer: Fluoromethane