The intermolecular force present in all molecules is the London dispersion force.
This force arises from temporary fluctuations in electron distribution around atoms, creating temporary dipoles. These temporary dipoles induce dipoles in neighboring molecules, leading to a weak attractive force.
London dispersion forces are present in all molecules, regardless of their polarity, because all molecules have electrons. However, they are generally weaker than other intermolecular forces like dipole-dipole interactions and hydrogen bonding.
The strength of London dispersion forces increases with increasing molecular size and surface area. This is because larger molecules have more electrons, which can more easily fluctuate and create larger temporary dipoles.
Here are some examples of how London dispersion forces play a role in everyday life:
- Liquefaction of gases: London dispersion forces are responsible for the liquefaction of noble gases, which are nonpolar.
- Boiling point of hydrocarbons: The boiling points of hydrocarbons increase with increasing chain length due to the increasing strength of London dispersion forces.
- Solubility of nonpolar substances: Nonpolar substances are more soluble in nonpolar solvents because of the weaker London dispersion forces between them.
