The dipole moment of the hydrogen chloride HCl molecule is approximately 1.08 Debye D .The bond in HCl is polar because of the difference in electronegativity between hydrogen H and chlorine Cl atoms. Electronegativity is a measure of an atom's ability to attract electrons in a chemical bond. In HCl, chlorine has a higher electronegativity value 3.16 compared to hydrogen 2.20 . This difference in electronegativity causes the electrons in the bond to be more attracted to the chlorine atom, creating a partial negative charge - on the chlorine and a partial positive charge + on the hydrogen. This separation of charges results in a polar bond and gives the molecule a dipole moment.