Say we have an HCl molecule. The difference in electronegativities of the H and Cl atoms tells us how polar the HCl molecule is. The dipole moment is also a measure of the degree of polarity in molecules.

So why do we need the "dipole moment" concept if we can see how polar a molecule is by looking at the electronegativities of the atoms in the molecule? Is it because in complex molecules it is easier to measure how polar a molecule is, using the dipole moment formula?

  • $\begingroup$ Hello and welcome to Chemistry.SE. If you have any questions regarding how the site works, please feel free to take the short tour or visit the help center. Best of luck with your question! $\endgroup$
    – airhuff
    Apr 18 '17 at 20:34
  • $\begingroup$ Well, electronegativity difference tells us like almost nothing. $\endgroup$
    – Mithoron
    Apr 18 '17 at 20:35
  • 5
    $\begingroup$ Dipole moment is a measure. Electronegativity is but a vague hint. $\endgroup$ Apr 18 '17 at 20:35
  • $\begingroup$ As @Ivan Neretin writes, the dipole moment is the experimental measurement so comes first , so you have your ideas the wrong way round. $\endgroup$
    – porphyrin
    Apr 19 '17 at 7:28
  • $\begingroup$ Electronegativities can only qualitatively predict the nature of a bond in a molecule. For quantitative requirements,the concept of dipole moment is required. $\endgroup$ Apr 24 '17 at 15:37

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.