Relative strength of intermolecular forces in small molecules:
Hydrogen bonds > Dipole-dipole interactions > London DIspersion Forces.
It takes two conditions for molecules in a substance to form hydrogen bonds.
NH₃ contains N-H bonds. The central nitrogen atom in an NH₃ molecule has one lone pair of electrons. NH₃ meets both conditions; it is capable of forming hydrogen bonds.
CCl₄ molecules are nonpolar. The molecule has a tetrahedral geometry. Dipole from the polar C-Cl bonds cancel out due to symmetry. The molecule is nonpolar overall. As a result, only London Dispersion Force is possible between CCl₄ molecules.
HCl molecules are polar. The H-Cl bond is fairly polar. The HCl molecule is asymmetric, such that the dipole won't cancel out. The molecule is overall polar. Both dipole-dipole interactions and London Dispersion Force are possible between HCl molecules. However, dipole-dipole interactions are most predominant among the two.
