Chapter 4 #25

(Polar molecules, Non-polar molecules, etc.)

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Ashley Davis 1I
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Joined: Fri Sep 29, 2017 7:04 am

Chapter 4 #25

Postby Ashley Davis 1I » Tue Nov 14, 2017 8:36 pm

Could someone explain to me why 1) you wouldn't arrange CH2Cl2 with H's and Cl's opposite to each other and 2) it's a polar molecule? I thought it might be nonpolar if you arrange them symmetrically...

Emily Oren 3C
Posts: 50
Joined: Fri Sep 29, 2017 7:07 am

Re: Chapter 4 #25

Postby Emily Oren 3C » Tue Nov 14, 2017 9:14 pm

This question is actually really misleading because while it looks like you can place the Cl atoms opposite each other and therefore cancel the dipole moments if you just use the Lewis Structure, if you look at the molecule's shape you can see that this doesn't work. CH2Cl2 has four regions of electron density so is tetrahedral. This means that no matter where you put the Cl atoms around the C atom they will never be opposite each other and the charges won't cancel.
Here's some pictures to help you visualize what I just said:
http://www.biochemhelp.com/images/CH2Cl2-lewis.jpg
https://upload.wikimedia.org/wikipedia/ ... -balls.png
I hope that helps!


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