Which shape

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

Moderators: Chem_Mod, Chem_Admin

annikaying
Posts: 94
Joined: Sat Sep 14, 2019 12:16 am

Which shape

Postby annikaying » Thu Nov 21, 2019 10:30 am

How do you determine if the shape formed will be polar or non polar? For example if a molecule can be either cis or trans(CCl2H2) how do you tell if you are asked to determine if the molecule is polar or non polar?

Rida Ismail 2E
Posts: 139
Joined: Sat Sep 07, 2019 12:16 am

Re: Which shape

Postby Rida Ismail 2E » Thu Nov 21, 2019 11:09 am

it depends on the atoms but in the case of C2H2Cl2 that can be cis or trans. Cis means that the Cl and H are on the same sides. This would be polar because there is a heavy pull on one side and not such a strong pull on the other side. in the trans molecule the Cl and H are distributed opposite from each other so the strong pull of Cl is countered by the other Cl and the H is countered by the other H

Izzie Capra 2E
Posts: 103
Joined: Sat Sep 07, 2019 12:19 am

Re: Which shape

Postby Izzie Capra 2E » Thu Nov 21, 2019 11:13 am

All the atoms surrounding the central atom must be the same in order for the molecule to be non-polar. Since there is Cl and H, that means this molecule will be non-polar because of the electronegativity differences, and the dipoles will not cancel out. The molecule can be either cis or trans, but it will still be non polar regardless in this situation.

Jenna Ortiguerra 4G
Posts: 50
Joined: Sat Aug 17, 2019 12:18 am

Re: Which shape

Postby Jenna Ortiguerra 4G » Thu Nov 21, 2019 1:53 pm

Nonpolar molecules have zero dipole moment while polar molecules have a nonzero dipole moment. CCl2H2 is polar because the difference in electronegativity between Cl and H are different which creates a difference in dipole moment between the central atom, making it nonzero.

Mitchell Koss 4G
Posts: 128
Joined: Sat Jul 20, 2019 12:17 am

Re: Which shape

Postby Mitchell Koss 4G » Thu Nov 21, 2019 2:07 pm

It is helpful to watch a YouTube video explaining the difference as many can be determined without looking at Lewis diagram

AprilPaz
Posts: 51
Joined: Wed Sep 18, 2019 12:18 am

Re: Which shape

Postby AprilPaz » Fri Nov 22, 2019 2:06 am

If the dipoles in the molecule do not cancel out, then the molecule will be polar.

Anthony Hatashita 4H
Posts: 103
Joined: Wed Sep 18, 2019 12:21 am

Re: Which shape

Postby Anthony Hatashita 4H » Fri Nov 22, 2019 3:02 am

Dipoles have to cancel out or it will be polar. I think it helps to look for symmetry in molecules and atoms within molecules to find if something is polar.


Return to “Determining Molecular Shape (VSEPR)”

Who is online

Users browsing this forum: No registered users and 2 guests