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### Polar vs Nonpolar

Posted: Sun Nov 11, 2018 11:45 am
How do you determine if the molecule is polar or non polar? Do you determine it from the Lewis structure or are there other steps involved?

### Re: Polar vs Nonpolar

Posted: Sun Nov 11, 2018 11:54 am
You can determine if a molecule is polar or nonpolar from the Lewis Structure. If the molecule has no polar bond than it will be nonpolar. Also, if the molecure has polar bonds, but the dipole moments are equal and in opposite directions, then the molecule is nonpolar. If the molecule is has polar bonds, but the dipole molecules are not equal and/or in opposite directions, then the molecule is polar.

### Re: Polar vs Nonpolar

Posted: Sun Nov 11, 2018 11:59 am
If the atoms have different electronegativities, this results in unequal sharing of electrons, which is polar. If the electronegativity difference equals zero, there is no unequal sharing and the molecule is nonpolar.

### Re: Polar vs Nonpolar

Posted: Sun Nov 11, 2018 12:54 pm
Polarity is also largely in part due to the shape of the electron. When an electrons has lone pairs of electrons amidst other atoms, it is likely to be polar. Similarly, a bond between three atoms all of which include different electronegativity, is likely to results in a polar molecule.

### Re: Polar vs Nonpolar

Posted: Sun Nov 11, 2018 12:58 pm
In addition to looking at the Lewis Structure for the dipole moments, I think the difference in electronegativity can be calculated to differentiate between polar and nonpolar molecules. For example, polar molecules tend to have higher differences in electronegativities than nonpolar ones.

### Re: Polar vs Nonpolar

Posted: Sun Nov 11, 2018 10:37 pm
When there is a difference in electronegativity, one atom is going to have more of a pull on that electron that the other, meaning the electrons will spend more of their time near that atom, so the negativity will be largely on that side of the molecule. That side of the molecule thus has a partial negative dipole where as the other side spends less time with the electron so it will have a partial positive dipole.