Final answer:
The boiling point of a molecule is determined by its intermolecular forces. The substance with the weakest intermolecular forces will have the lowest boiling point.
Step-by-step explanation:
The boiling point of a molecule is determined by its intermolecular forces. The molecules with the weakest intermolecular forces will have the lowest boiling point. Some common examples of intermolecular forces are hydrogen bonding, dipole-dipole interactions, and London dispersion forces.
For example, in a group of compounds with similar molecular weights, the one with hydrogen bonding will have the highest boiling point, followed by the compound with dipole-dipole interactions, and finally the compound with only London dispersion forces will have the lowest boiling point.
The strength of intermolecular forces can also be affected by the surface area of the molecule. Larger molecules with more surface area tend to have stronger intermolecular forces and higher boiling points.