What type of interactions describe the attraction between polar molecules?

The attraction between polar molecules is best described by dipole-dipole interactions. Polar molecules have permanent dipoles due to the difference in electronegativity between the atoms within the molecule. This results in one end of the molecule being slightly negative and the other end being slightly positive.

When two polar molecules come close to each other, the positive end of one molecule is attracted to the negative end of another molecule, leading to dipole-dipole interactions. These interactions are significant in determining the physical properties of substances composed of polar molecules, such as boiling points and solubility.

Other types of interactions mentioned do not accurately describe the specific attraction between polar molecules. Dispersion forces, or London forces, arise from temporary fluctuations in electron density and are typically observed in nonpolar molecules. Hydrogen bonds, while a specific type of dipole-dipole interaction occurring between hydrogen and highly electronegative atoms (like oxygen or nitrogen), are not present in all polar molecules. Ionic bonds, on the other hand, involve the electrostatic attraction between fully charged ions and are not applicable to neutral polar molecules. Therefore, dipole-dipole interactions effectively capture the nature of attraction between polar molecules.