Saedius t1_iv3umb1 wrote
Yes - because geometry matters. Carbon dioxide is non-polar because the individual bond dipole moments are equal in magnitude and opposite in direction, leading them cancelling each other out. So if we consider the bond polarity and the relative orientation then we can deduce the overall polarity.
Carbontetrachloride? Four polar bonds, but they are evenly spaced about a tetrahedron, so no net dipole moment. Chloroform, dichloromethane, and chloromethane, where the symmetry is broken? All polar to greater or lesser extent.
I recommend that in analyzing a molecule, you start with the Lewis structure in an approximately accurate orientation of the atoms. Doing so for ozone reveals two things. One that the molecule is bent and has no charge neutral octet Lewis structure. That's a big hint that (a) electron distribution in the molecule isn't just due to polarity and (b) the lack of symmetry means that it's unlikely that the uneven charge distribution will be canceled out.
There's also a fair number of polar molecules where all the atoms are roughly the same electronegativity but due to the nature of charge distribution in the ground state (which often can be approximated with Lewis structures) lead to a dipole. The best example might be azulene, which is a hydrocarbon with a large dipole moment due to the molecular orbital arrangement of the p-orbitals of the carbon atoms. https://en.wikipedia.org/wiki/Azulene
Hidden-Felon OP t1_iv6ggz7 wrote
Thank you so much for the detailed response!
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