Force existing between molecules of alkanes in liquid and solid stat

Question

what is the force existing between molecules of alkanes in liquid and solid stat

Answer 1

Alkanes are generally nonpolar and therefore you would not expect to see hydrogen bonding or dipole-dipole interactions.  That leaves London dispersion forces as the main force that provides the intermolecular attraction that keep alkanes as liquids or solids.

London dispersion forces depend on the polarizability of a molecule.  The more electrons a molecule has, and a greater volume throughout which the electrons can move, will make for greater polarizability.

In some cases London dispersion forces can be as great as dipole-dipole interaction.