Lone pair placement

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

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Lone pair placement

Postby KNguyen_1I » Mon Nov 18, 2019 4:27 pm

When determining the VSEPR model for a molecule with lone pairs (such as in the case of SF4 where there exists a lone pair, the reason why we chose to put the lone pair on the equatorial position axes than the other one is because it repels less? Therefore is most stable. So essentially, we place the lone pairs on the axes where there exists the least amount of repulsion to its surroundings in order to determine VSEPR shape.

Rita Chen 1B
Posts: 112
Joined: Sat Jul 20, 2019 12:15 am

Re: Lone pair placement

Postby Rita Chen 1B » Mon Nov 18, 2019 4:33 pm

I think that you place it where it will have the largest distance so that it will stabilize the structure. Not sure if that is completely correct, I am confused a little too.

Ruby Richter 2L
Posts: 103
Joined: Thu Jul 25, 2019 12:17 am

Re: Lone pair placement

Postby Ruby Richter 2L » Mon Nov 18, 2019 4:46 pm

Yes. Lone pairs have a stronger repelling effect than bonds because the electron cloud can spread over a larger volume. This means that the lowest energy/most stable structure is achieved when atoms bonded to the central atom are furthest from lone pairs, and when lone pairs are furthest from each other.

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