Answer:
The intermolecular forces increase in the following order:
C2H6 < CH4 < CH3F < NH3
The reasoning behind this order is as follows:
C2H6 (ethane) is a nonpolar molecule with only dispersion forces, which are the weakest intermolecular forces.
CH4 (methane) is also nonpolar and only has dispersion forces, but it has a slightly larger molecular weight than ethane, which leads to stronger dispersion forces.
CH3F (fluoromethane) is polar and has dipole-dipole forces in addition to dispersion forces. The dipole-dipole forces are stronger than the dispersion forces in this case.
NH3 (ammonia) is also polar and has hydrogen bonding, which is a stronger type of dipole-dipole force.
Step-by-step explanation: