#4.25 Predicting Polarity of a molecule?

Moderators: Chem_Mod, Chem_Admin

Adriana Rangel 1A
Posts: 96
Joined: Fri Sep 29, 2017 7:04 am

#4.25 Predicting Polarity of a molecule?

Postby Adriana Rangel 1A » Tue Nov 21, 2017 9:55 pm

So I drew the Lewis Structure for a) CH2Cl2 and drew it out with C as the central atom and two Cl attached to it (single bond) and two H atoms attached to it (single bond). How can I predict polarity? I know that a molecule is nonpolar when the dipoles cancel each other out and polar when the dipoles don't cancel.
So, I happened to draw the compound with Cl being on the same side and H being on the same side. When they are positioned like that, the dipoles don't cancel out and it results in it being polar.
But if I had decided to draw the compound with Cl being on opposite sides of each other and H being on opposite sides of each other, then wouldn't the dipoles cancel out and therefore it would be nonpolar?

How do you know when to place the atoms of the same elements opposite to each other when drawing a Lewis structure?

Ethan-Van To Dis2L
Posts: 50
Joined: Fri Sep 29, 2017 7:05 am

Re: #4.25 Predicting Polarity of a molecule?

Postby Ethan-Van To Dis2L » Wed Nov 22, 2017 1:20 am

This is where you would use VSPER. CH2Cl2 is a tetrahedral structure which is shown here Image

Since Cl2 is more electronegative, it will be partially negative on one side of the molcule making the opposite partially positive meaning the molecule is polar.


Return to “Polarisability of Anions, The Polarizing Power of Cations”

Who is online

Users browsing this forum: No registered users and 1 guest