What is the realtionship between degree of polarity and the strength of imfs experiences by molecules?

The polarity of a molecule is given by the difference of electronegativity between the atoms that form that molecule.

In simple words, this difference will create inside the molecule areas with deficiency of electrons (positive pole) and areas with excess of electrons (negative pole).

Oposite poles attract to each other due to the oppisite charges, so when two polar molecules interact they form a dipole-dipole intermolecular force.

The higher the difference of electronegativity, the higher the polarity. Also, the higher the polarity, the strongher the dipole-dipole force and therefore the strenght of the intermolecular forces.