Answer:
E. CH₄ < CH₃Cl < CH₃OH < RbCl
Explanation:
The molecule with the stronger intermolecular forces will have the higher boiling point.
The order of strength of intermolecular forces (strongest first) is
- Ion-Ion
- Hydrogen bonding
- Dipole-dipole
- London dispersion
RbCl is a compound of a metal and a nonmetal. It is an ionic compound, so it has the highest boiling point.
CH₃Cl has a C-Cl polar covalent bond. It has dipole-dipole forces, so it has the second lowest boiling point.
CH₃OH has an O-H bond. It has hydrogen bonding, so it has the second highest boiling point.
CH₄ has nonpolar covalent C-H bonds. It has only nonpolar bonds, so the only attractive forces are London dispersion forces. It has the lowest boiling point.
Thus, the order of increasing boiling points is
CH₄ < CH₃Cl < CH₃OH < RbCl
