The relationship between the strength of intermolecular forces and the boiling point of a substance in organic molecules with various functional groups is that stronger intermolecular forces generally lead to higher boiling points. This is because more energy is required to overcome the stronger forces holding the molecules together in the liquid phase, allowing them to transition into the gas phase.There are three main types of intermolecular forces in organic molecules:1. London dispersion forces: These are weak, temporary forces that exist between all molecules, regardless of their polarity. They result from the temporary uneven distribution of electrons in the molecule, creating temporary dipoles. The strength of London dispersion forces increases with the size and shape of the molecule.2. Dipole-dipole forces: These forces exist between polar molecules, where there is a permanent uneven distribution of electrons, creating a permanent dipole. The strength of dipole-dipole forces depends on the difference in electronegativity between the atoms involved and the distance between the molecules.3. Hydrogen bonding: This is a special type of dipole-dipole interaction that occurs when hydrogen is bonded to a highly electronegative atom, such as oxygen, nitrogen, or fluorine. Hydrogen bonding is stronger than regular dipole-dipole forces due to the small size and high charge density of the hydrogen atom.To predict the boiling points of different compounds, consider the functional groups present in the molecules and the types of intermolecular forces they can form. Molecules with stronger intermolecular forces, such as hydrogen bonding, will generally have higher boiling points than those with weaker forces, like London dispersion forces.For example, compare two compounds: ethanol CH3CH2OH and propane CH3CH2CH3 . Ethanol has a hydroxyl group -OH , which can form hydrogen bonds, while propane only has London dispersion forces. As a result, ethanol has a higher boiling point 78.37C than propane -42.1C .In summary, the strength of intermolecular forces is directly related to the boiling point of a substance in organic molecules with various functional groups. By analyzing the functional groups and the types of intermolecular forces present, you can predict the relative boiling points of different compounds.