Discuss the melting and boiling points of haloalkanes and haloarenes.

(N/A) At room temperature: Methyl chloride $(CH_3Cl)$,methyl bromide $(CH_3Br)$,ethyl chloride $(CH_3CH_2Cl)$,and some chlorofluoromethanes are gases at room temperature,while higher members are liquids or solids.
$(b)$ Boiling points of organic halogen compounds: Organic halogen compounds are generally polar. Due to $(i)$ greater polarity and $(ii)$ higher molecular mass as compared to the parent hydrocarbons,the intermolecular forces of attraction (dipole-dipole and van der Waals) are stronger in halogen derivatives of alkanes. Consequently,the boiling points of chlorides,bromides,and iodides are considerably higher than those of the hydrocarbons of comparable molecular mass.
$(c)$ Boiling point and attraction forces: As the size and number of electrons in the molecules increase,the magnitude of van der Waals forces of attraction increases,resulting in an increase in boiling points,as shown in the figure.
$(d)$ Order of boiling points of alkyl halides: For the same alkyl group,the decreasing order of boiling points of alkyl halides is $RI > RBr > RCl > RF$. This is because as the mass and size of the halogen atom increase,the magnitude of van der Waals forces of attraction increases.