Lone Pairs

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

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Reese - Dis 1G
Posts: 31
Joined: Fri Sep 28, 2018 12:15 am

Lone Pairs

Postby Reese - Dis 1G » Thu Nov 15, 2018 10:28 pm

When you have more than one lone pair on an atom, do they have to be opposite eachother to balance out the repulsion? Or can they be anywhere on the atom?

Gabriela Aguilar 4H
Posts: 30
Joined: Fri Sep 28, 2018 12:29 am

Re: Lone Pairs

Postby Gabriela Aguilar 4H » Thu Nov 15, 2018 10:43 pm

It mostly depends on the repulsion;

Lone-lone pair > lone - bonding pair > bonding-bonding pair replusion.

timschaeffer Dis 1J
Posts: 38
Joined: Fri Sep 28, 2018 12:18 am

Re: Lone Pairs

Postby timschaeffer Dis 1J » Thu Nov 15, 2018 10:44 pm

When a central atom has multiple lone pairs, they don't necessarily have to be opposite of one another. This is because sometimes multiple other atoms attached to the central atom will end up pushing the two lone pairs into an orientation where they are closer together. The table below shows some examples of how lone pairs can orient themselves as points of a tetrahedron and as points of a trigonal plane, all of which have bond angles substantially less than 180 degrees.

VSEPR.png

Dakota_Campbell_1C
Posts: 51
Joined: Fri Sep 28, 2018 12:15 am

Re: Lone Pairs

Postby Dakota_Campbell_1C » Thu Nov 15, 2018 11:57 pm

Is it fair to say that if there is a lone pair on the central atom that the molecule is going to be polar? Most of the examples I'm seeing demonstrate this point? Will there be more electron density there, therefore, repelling the other atoms creating a dipole.


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