UNIT # 5 - COMPOUNDS

5.7 - Polarity of Molecules

In some molecules, when all the bond dipole moments are summed together, the overall dipole moment is zero. In such a case, the molecule is said to be nonpolar.

Is carbon dioxide polar or nonpolar?


In other molecules, when all the dipole moments are summed up, there is a net dipole moment.

Do you know how to explain that water is a polar molecule?

In summary,

to determine whether a molecule is polar or not, we need to sum up all the bond dipole moments of the molecule by adding up all its bond dipole moments (ie - vectors).

When the molecule does not possess a net dipole moment, the molecule is nonpolar.


When the molecule possesses a net dipole moment, the molecule is polar.



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