polar vs nonpolar

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Jordan_OBrien_2k
Posts: 53
Joined: Wed Sep 30, 2020 9:43 pm

polar vs nonpolar

Postby Jordan_OBrien_2k » Sun Nov 15, 2020 9:12 pm

Hi, I'm having difficulties with determining whether something is polar or nonpolar. Can someone explain how to find this or different tips that they have to do this?

Natalie 3k
Posts: 86
Joined: Wed Sep 30, 2020 10:11 pm

Re: polar vs nonpolar

Postby Natalie 3k » Sun Nov 15, 2020 9:26 pm

First look at whether the bonds are polar or not by looking at electronegativity, and if there are no polar bonds then the molecule is non polar. If there are polar bonds, look at the arrangement of the molecule and if it is not symmetrical, then the molecule is polar. I have a hard time with this too so hopefully someone else can add more!

Lucy Wang 2J
Posts: 86
Joined: Wed Sep 30, 2020 10:09 pm
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Re: polar vs nonpolar

Postby Lucy Wang 2J » Sun Nov 15, 2020 9:26 pm

If a molecule is polar, that means the charge distribution will be unequal.
For example, in the molecule HF it would be polar because F is much more electronegative than H and therefore will have a stronger pull on the electrons. Making the F side of the molecule slightly more negative than the H side, this is a dipole. However in N2, since it is the same element and they have the same electronegativity, that means there is an even pull on the electrons so it is non-polar.

Sometimes though, even if the charges are unbalanced, the geometry of the molecule will cause them to be cancelled out. For example in CCl4, the bonds between the C-Cl are polar because of the electronegativity differences, but the overall molecule is non-polar because its tetrahedral structure cancels them out.

Nathaly Cruz 2D
Posts: 55
Joined: Wed Sep 30, 2020 10:06 pm

Re: polar vs nonpolar

Postby Nathaly Cruz 2D » Sun Nov 15, 2020 9:36 pm

Lucy Wang 1A wrote:If a molecule is polar, that means the charge distribution will be unequal.
For example, in the molecule HF it would be polar because F is much more electronegative than H and therefore will have a stronger pull on the electrons. Making the F side of the molecule slightly more negative than the H side, this is a dipole. However in N2, since it is the same element and they have the same electronegativity, that means there is an even pull on the electrons so it is non-polar.

Sometimes though, even if the charges are unbalanced, the geometry of the molecule will cause them to be cancelled out. For example in CCl4, the bonds between the C-Cl are polar because of the electronegativity differences, but the overall molecule is non-polar because its tetrahedral structure cancels them out.


Thank you. This helped so much!


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