Final answer:
Methylene Chloride (CH₂Cl₂) is polar due to its molecular geometry and polar C-Cl bonds with a dipole moment, unlike Carbon Tetrachloride (CCl₄), which is nonpolar due to symmetrical bond moment cancellation. This results in CH₂Cl₂ having stronger dipole-dipole interactions and a higher boiling point compared to CCl₄.
Step-by-step explanation:
Methylene Chloride (CH₂Cl₂) has a higher polarity than Carbon Tetrachloride (CCl₄) mainly because of its molecular geometry and the presence of polar bonds. Methylene Chloride is a polar molecule with two polar C-Cl bonds and an overall dipole moment. This happens because of the different electronegativities of carbon and chlorine, where chlorine is more electronegative than carbon. These bond moments do not cancel out due to the geometry of the molecule, resulting in a net dipole moment, hence the higher polarity. In contrast, Carbon Tetrachloride, which also has polar C-Cl bonds, is nonpolar because it has a symmetrical tetrahedral shape wherein the bond moments cancel out, leading to no net dipole moment. Therefore, Methylene Chloride experiences dipole-dipole interactions, which contribute to its polarity and are stronger than the dispersion forces in nonpolar molecules like Carbon Tetrachloride. This also explains why CH₂Cl₂ has a higher boiling point compared to nonpolar molecules of similar molar mass.