Why Alkyl halides have higher boiling points than alkanes?

The boiling points of alkyl halides are considerably higher than those of the corresponding alkanes. The main reason for this is the dipole moment of alkyl halides, which leads to attractive dipole-dipole interactions in liquid alkyl halides. Furthermore, the higher molar mass and the strongerLondon forces(Cl, Br and I) lead to higher boiling points. The main reason of stronger London forces between alkyl halides is the fact that the electron shell of halogens is larger than that of hydrogen and carbon. In larger electron shells, the electrons are not as strongly attracted by the nucleus as is the case in small electron shells. Consequently, the interactions between the electron shells of larger atoms are stronger.