Organic Halogen Compounds

The boiling points of organic halogen compounds are generally higher than the parent hydrocarbons due to their greater polarity and higher molecular mass, which results in stronger intermolecular forces of attraction such as dipole-dipole and van der Waals forces.

The boiling points of chlorides, bromides, and iodides are considerably higher than those of hydrocarbons with comparable molecular mass due to the stronger intermolecular forces of attraction in the halogen derivatives, caused by their greater polarity and higher molecular mass compared to the parent hydrocarbons.

For the same alkyl group, the boiling points of alkyl halides decrease in the order: RI > RBr > RCl > RF, due to the increase in size and mass of the halogen atom, leading to stronger intermolecular forces of attraction.

The magnitude of van der Waals forces increases with the increase in size and mass of the halogen atom in alkyl halides, leading to stronger intermolecular attractions as the molecules get bigger in size and have more electrons.

The differences in boiling points of methyl chloride, methyl bromide, ethyl chloride, and chlorofluoromethanes at room temperature are mainly due to their varying molecular masses and polarities, which affect the strength of intermolecular forces of attraction.