Lone Pairs for AX4E

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

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ALegala_2I
Posts: 102
Joined: Thu Jul 11, 2019 12:17 am

Lone Pairs for AX4E

Postby ALegala_2I » Wed Nov 20, 2019 8:57 am

For a seesaw shaped molecule, how do you know that the lone pair should be on the equatorial plane and not the axial plane?

GFolk_1D
Posts: 101
Joined: Fri Aug 09, 2019 12:15 am

Re: Lone Pairs for AX4E

Postby GFolk_1D » Wed Nov 20, 2019 9:03 am

The lone pairs are placed based on repulsion strengths:

lone pr-lone pr>lone pr-bond pr>bond pr-bond pr

Therefore, by placing the lone pair on the equatorial plane, it allows for repulsion strengths to play out

Wendy 1E
Posts: 111
Joined: Sat Aug 17, 2019 12:17 am
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Re: Lone Pairs for AX4E

Postby Wendy 1E » Wed Nov 20, 2019 10:09 am

When the lone pair is in the equatorial plane, it is only perpendicular to two atoms. If the lone pair was in the axial plane, it would be perpendicular to three atoms. Therefore, having a lone pair in the equatorial plane would minimize the repulsions created by the lone pair.

EricZhao3G
Posts: 51
Joined: Tue Oct 08, 2019 12:16 am

Re: Lone Pairs for AX4E

Postby EricZhao3G » Wed Nov 20, 2019 11:37 am

If the lone pair was on the axial plane, it would have a 90 degrees bond angle with 3 atoms. With the lone pair on the equatorial plane, it would have a 90 degrees bond with only 2 atoms. There is less repulsion by putting the lone pair on the equatorial plane so it should be there.


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