a.) HCl b.) PH3 c.) Xe
Work Step by Step
a.) HCl has a lower boiling point because its dipole-dipole forces are weaker than the ionic bonds present in LiCl. b.) PH3 has lower boiling point since it has dipole-dipole forces but lacks hydrogen bonding (since it has only P-H bonds). NH3 has hydrogen bonding due to its N-H bonds, giving it stronger intermolecular forces. c.) Xe and I2 are both nonpolar and thus have London forces only. But Xe's dispersion forces are weaker because it is smaller and therefore less polarizable compared to I2.