London dispersion forces are weak intermolecular forces that work to attract both polar and nonpolar molecules to one another via instantaneous dipole moments. These are extremely short-lived fluctuations in the distribution of electrons around an atom. London forces are extremely sensitive to distance, being inversely proportional to the distance raised to the seventh power. They are also sensitive to the size of the molecules, because greater surface area allows for more molecular interaction
Place these hydrocarbons in order of decreasing boiling point:
paraffin : C36H74
methane: CH4
octane: C8H18
isooctane:C8H18 ( also known as 2,2,4 trimethylpentane)
octadecane: C18H36
Rank from highest to lowest boiling point. can also be equivalent.