lone pairs -polar molecule
Moderators: Chem_Mod, Chem_Admin
-
- Posts: 107
- Joined: Wed Sep 30, 2020 9:39 pm
- Been upvoted: 1 time
lone pairs -polar molecule
If any of the elements within the atom have a lone pair, could you automatically assume that it is a polar molecule?
-
- Posts: 101
- Joined: Wed Sep 30, 2020 9:41 pm
- Been upvoted: 1 time
Re: lone pairs -polar molecule
Hi Bethany! I would say no because if you have a diatomic molecule such as Br2, in which each Br atom has 3 lone pairs, but it is still a nonpolar molecule. Rather than just looking for lone pairs, I would say to look at the difference in electronegativity to determine polarity :)
- Attachments
-
- main-qimg-5f02d01937a84f86a0ef494dadc98f6e.png (13.4 KiB) Viewed 110 times
Last edited by Yu Jin Kwon 3L on Sat Nov 28, 2020 11:22 am, edited 1 time in total.
-
- Posts: 103
- Joined: Wed Sep 30, 2020 9:39 pm
- Been upvoted: 3 times
Re: lone pairs -polar molecule
I don’t think you can assume that any molecule with a central atom that has lone pairs is polar. For example, XeF2 is non polar, and it has 3 lone pairs on the central atom. The lone pairs are arranged at 120 degrees to each other and the F-Xe-F bond angle is 180 degrees, so there is a 0 net dipole moment due to this symmetry.
Re: lone pairs -polar molecule
I wouldn't say that would be the case for every molecule. For example, for compounds like H2, Cl2, etc. are all considered non polar.
-
- Posts: 93
- Joined: Wed Sep 30, 2020 9:35 pm
- Been upvoted: 1 time
-
- Posts: 107
- Joined: Wed Sep 30, 2020 10:03 pm
- Been upvoted: 1 time
Re: lone pairs -polar molecule
You cannot assume this because of the fact that if the molecule is symmetrical the charges might cancel out despite the atoms having lone pairs.
-
- Posts: 91
- Joined: Wed Sep 30, 2020 9:35 pm
- Been upvoted: 1 time
Re: lone pairs -polar molecule
In some molecules, the presence of a lone pair causes the molecule to lose its symmetry, therefore its dipoles would not cancel out causing it to be a polar molecule. But as many have mentioned, lone pairs are not determinedly a factor of polar molecules. It is best to look at how the lone pairs are a factor in molecule shape to determine its polarity.
-
- Posts: 90
- Joined: Wed Sep 30, 2020 10:07 pm
Re: lone pairs -polar molecule
I would definitely first look at the bond angles, because not every molecule with lone pairs would be polar as they could be evenly spaced from each other
-
- Posts: 78
- Joined: Wed Sep 30, 2020 9:59 pm
Re: lone pairs -polar molecule
Hi, I wouldn't assume that if a molecule has lone pairs it would be polar, since for example diatomic molecules do have lone pairs but are nonpolar because the dipole moments cancel out.
-
- Posts: 92
- Joined: Wed Sep 30, 2020 10:11 pm
Re: lone pairs -polar molecule
i dont think that would be accurate. I would say just look at the geometry of the molecule
-
- Posts: 52
- Joined: Mon Jan 06, 2020 7:27 am
Re: lone pairs -polar molecule
No because there is still a possibility that they might be non-polar.
Return to “Ionic & Covalent Bonds”
Who is online
Users browsing this forum: No registered users and 1 guest