Lone pairs

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

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Hannah_1G
Posts: 100
Joined: Wed Sep 18, 2019 12:22 am

Lone pairs

Postby Hannah_1G » Wed Nov 20, 2019 10:10 pm

Do lone pairs not on the center atom account for shape? For example HCN

105194078
Posts: 52
Joined: Thu Sep 19, 2019 12:17 am

Re: Lone pairs

Postby 105194078 » Wed Nov 20, 2019 10:24 pm

I don't think so. The way I drew that specific molecule you gave was that I put a triple bond between C and N and the H on the left side of C. I don't think the lone pairs in N account for its shape in this particular example. However, someone correct me if I'm wrong.

Abigail Sanders 1E
Posts: 112
Joined: Wed Sep 11, 2019 12:16 am

Re: Lone pairs

Postby Abigail Sanders 1E » Wed Nov 20, 2019 11:02 pm

Lone pairs not on the central atom do not account for the shape of the central atom. However, lone pairs on an outside atom do account for the electron and molecular structure of that atom.

Cassandra_1K
Posts: 49
Joined: Wed Sep 18, 2019 12:16 am

Re: Lone pairs

Postby Cassandra_1K » Thu Nov 21, 2019 6:43 pm

Only the lone pairs on the central atom account for shape!

Miriam Villarreal 1J
Posts: 105
Joined: Sat Aug 17, 2019 12:16 am

Re: Lone pairs

Postby Miriam Villarreal 1J » Fri Nov 22, 2019 10:46 am

Only lone pairs present on the central atom are considered when determining shape an dcounting the number of areas with e- density.

Ashley Kim 3F
Posts: 50
Joined: Thu Jul 25, 2019 12:17 am

Re: Lone pairs

Postby Ashley Kim 3F » Fri Nov 22, 2019 11:17 am

Lone pairs on the central atom account for the electronic arrangement of a molecule and sometimes for the shape of the molecule.

derinceltik1K
Posts: 51
Joined: Sat Aug 17, 2019 12:15 am

Re: Lone pairs

Postby derinceltik1K » Fri Nov 22, 2019 6:14 pm

Lone pairs do count as 1 area of electron density. So with VSEPR you have to consider them. But while just drawing the lewis structure you don't have the account for the affect of the lone pair on other bonds. You just draw it and place the lone pairs. But for electron geometry, lone pairs will push the bonds away, distorting the theoretical bond angle.

Lauren Stack 1C
Posts: 100
Joined: Sat Aug 17, 2019 12:18 am

Re: Lone pairs

Postby Lauren Stack 1C » Fri Nov 22, 2019 6:26 pm

In the VSEPR theory that we use to name molecules, only the electrons associated with the central atom are considered. If you look at the VSEPR formula, which involved A-the central atom, X-number of bonds connected to the central atom, and E- number of lone pairs/a radical on the central atom. Thus, we are not considering lone pairs on other atoms when naming and describing shape using VSEPR.

Victoria Otuya 4F
Posts: 50
Joined: Wed Sep 18, 2019 12:21 am

Re: Lone pairs

Postby Victoria Otuya 4F » Fri Nov 22, 2019 6:47 pm

So the lone pairs makes up the shape of a molecule and it is also known to have an electron density. But why is it that it is counted as an electron density if its a lone pair?

Claire Grover 3G
Posts: 64
Joined: Wed Sep 18, 2019 12:18 am

Re: Lone pairs

Postby Claire Grover 3G » Fri Nov 22, 2019 8:09 pm

Only lone pairs on the central atom count for this!

AmyL_3L
Posts: 50
Joined: Fri Aug 09, 2019 12:17 am

Re: Lone pairs

Postby AmyL_3L » Sun Nov 24, 2019 10:54 am

Only the lone pairs on the central atom are significant in determining the molecular shape.

Rishika Yadav 3D
Posts: 53
Joined: Wed Sep 11, 2019 12:17 am

Re: Lone pairs

Postby Rishika Yadav 3D » Sun Nov 24, 2019 11:53 am

No, only on the central atom. Lone pairs on the outer atoms d not affect bond positioning with the central atom.

claribel charway 1I
Posts: 55
Joined: Wed Sep 11, 2019 12:15 am

Re: Lone pairs

Postby claribel charway 1I » Sun Nov 24, 2019 12:43 pm

the only lone pairs that matter are the ones on the central atom, for example it makes the difference between linear and bent

005162902
Posts: 102
Joined: Wed Sep 18, 2019 12:15 am

Re: Lone pairs

Postby 005162902 » Sun Nov 24, 2019 12:54 pm

Lone pairs on the central atom affect molecular shape. Like a bond, they represent a region of electron density on the atom and bend the bonds away from it because of electron repulsion.


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