The dipole moment of a molecule is a measure of its polarity, which is the separation of charges within the molecule. It is calculated using the formula:Dipole moment = Charge Q Distance d between the chargesIn the case of hydrogen chloride HCl , the molecule is polar due to the difference in electronegativity between hydrogen H and chlorine Cl atoms. The electronegativity values for hydrogen and chlorine are 2.20 and 3.16, respectively. This difference in electronegativity leads to a partial positive charge on the hydrogen atom and a partial negative charge on the chlorine atom.To calculate the dipole moment, we need to know the bond length distance between the charges and the charges on the atoms. The bond length of HCl is approximately 1.27 1.27 10 m . The charges on the atoms can be estimated using the electronegativity difference EN = 3.16 - 2.20 = 0.96 . The partial charges can be approximated as +0.2e on H and -0.2e on Cl, where e is the elementary charge 1.6 10 C .Now we can calculate the dipole moment: = Q d = 0.2 1.6 10 C 1.27 10 m 5.12 10 C.mThe dipole moment of HCl is approximately 5.12 10 C.m.The direction of the dipole moment points from the positive charge hydrogen to the negative charge chlorine . In the HCl molecule, it points from the hydrogen atom towards the chlorine atom.