Why is #"CHCl"_3# polar even though the electronegativity difference is smaller than #1.0#?
2 Answers
Yeah, when the electronegativity differences get this small, it's no longer practical to depend on the simple cutoffs for what counts as nonpolar, polar, and ionic.
You should start thinking about polarity as a spectrum (
- nonpolar
- slightly polar
- polar
- very polar
- ionic
In this case,
Blue is positive and red is negative in the above diagram.
Even though the typical cutoff assigns it as a nonpolar bond, the fact that molecule is asymmetrical and that a
There is a molecular dipole for any
Explanation:
The
And thus
As we add electrons to the molecule (by halogen substitution) the boiling point will naturally grow up because of the increase in intermolecular dispersion forces. And yet an extra force of intermolecular interaction by formation of a dipole. Compare non-polar methane, with slightly polar