Final answer:
CHCl3 exhibits the strongest dipole-dipole interactions due to its substantial dipole moment created by three highly electronegative chlorine atoms, resulting in stronger electrostatic attractions between molecules.
Step-by-step explanation:
The molecule that would exhibit the strongest dipole-dipole interactions among the given options is CHCl3 (trichloromethane). To determine this, we need to look at the polarity of the molecules. Polarity arises from an unequal distribution of electrons in the molecule's covalent bonds, leading to a separation of charge known as a dipole. With three chlorine atoms, CHCl3 has a more substantial dipole due to the high electronegativity of chlorine compared to hydrogen and carbon, leading to stronger dipole-dipole forces.
By comparison, CH4 is nonpolar, with no dipole moment. CH3Cl and CH2Cl2 possess dipole moments, but these are less than CHCl3 due to fewer chlorine atoms. More chlorine atoms in a molecule usually equate to a larger dipole moment because of the relative electronegativities of carbon and chlorine. Moreover, the bond moments in CHCl3 all point towards the Cl end of the molecule, contributing to its considerable dipole moment and resulting in more substantial dipole-dipole interactions.