Dipole-Dipole Forces

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Tyler Angtuaco 1G
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Joined: Wed Sep 11, 2019 12:16 am

Dipole-Dipole Forces

Postby Tyler Angtuaco 1G » Wed Nov 13, 2019 12:57 pm

When polar molecules are separated, how do their opposite partial charges on each molecule "merge and cancel" as stated in the textbook?

Posts: 66
Joined: Thu Jul 25, 2019 12:15 am

Re: Dipole-Dipole Forces

Postby 205296774 » Wed Nov 13, 2019 4:17 pm

The separation of the partial charges creates a dipole where one pole is partially negative and the other is partially positive. I think you are either referring to the overall charge being zero as the two opposite partial charges cancel, or most likely, when two polar molecules (which therefore each have two regions of partial negative charge and partial positive charge) bond: a partial positive of one molecule bonds with the partial negative of the other molecule, cancelling each other out.

Hope this helps!

Brianna Becerra 1B
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Joined: Fri Aug 02, 2019 12:16 am

Re: Dipole-Dipole Forces

Postby Brianna Becerra 1B » Thu Nov 14, 2019 9:14 am

An example of this can be seen with BeCl2. When drawing the structure, there are negative dipole charges on boh pf the Cl molecules. Because of this, the charges go away from each other and cancel out so the molecule is now nonpolar. This should not be confused with a molecule such as H20. In this Lewis structure, though the negative dipole is in the center and the arrows seem to cross out, they don't due the bent shape of H2O caused by the Lone pairs on the 0xygen. This molecule is then still polar.
Lewis structure for BeCl2:
http://img1.wikia.nocookie.net/__cb2013 ... /Becl2.png
Lewis Structure for H20:
http://opentextbc.ca/introductorychemis ... ucture.png

Victor James 4I
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Re: Dipole-Dipole Forces

Postby Victor James 4I » Thu Nov 14, 2019 7:02 pm

would these molecules that have canceled charges still have dipole-dipole interactions?

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