The boiling point of a substance with dipole-dipole interactions is generally higher than that of a substance with only London dispersion forces. The reason for this difference lies in the strength of the intermolecular forces present in each substance.Dipole-dipole interactions occur between polar molecules, which have a permanent separation of charges due to differences in electronegativity between the atoms within the molecule. This results in a positive end and a negative end, creating an attractive force between the oppositely charged ends of neighboring molecules. These interactions are relatively strong compared to London dispersion forces, and as a result, more energy in the form of heat is required to overcome these forces and cause the substance to boil.London dispersion forces, on the other hand, are present in all molecules, but they are the only intermolecular forces in nonpolar molecules. These forces arise from temporary fluctuations in electron distribution around the molecule, which create transient dipoles that induce dipoles in neighboring molecules. London dispersion forces are generally weaker than dipole-dipole interactions because they are based on temporary, rather than permanent, charge separations.In summary, substances with dipole-dipole interactions typically have higher boiling points than those with only London dispersion forces due to the stronger intermolecular forces present in polar molecules. This means that more energy is needed to overcome these forces and cause the substance to change from a liquid to a gaseous state.