Molecular Shape

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

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skyeblee2F
Posts: 62
Joined: Fri Sep 28, 2018 12:23 am

Molecular Shape

Postby skyeblee2F » Wed Dec 05, 2018 11:06 pm

IF5 has a VSEPR formula of AX5E but has a square pyramidal shape. Why doesn't it have a trigonal bipyramidal shape? Wouldn't the electron densities be more spaced out this way?
Last edited by skyeblee2F on Wed Dec 05, 2018 11:52 pm, edited 2 times in total.

Sarah Fatkin 4I
Posts: 71
Joined: Fri Sep 28, 2018 12:27 am

Re: Molecular Shape

Postby Sarah Fatkin 4I » Wed Dec 05, 2018 11:16 pm

Hi! IF5 would not have trigonal pyramidal shape because that would mean it would be AX3E (three bonds, one lone pair).

skyeblee2F
Posts: 62
Joined: Fri Sep 28, 2018 12:23 am

Re: Molecular Shape

Postby skyeblee2F » Wed Dec 05, 2018 11:52 pm

sorry, I meant trigonal bipyramidal, not pyramidal

Nicolette_Canlian_2L
Posts: 77
Joined: Fri Sep 28, 2018 12:25 am
Been upvoted: 1 time

Re: Molecular Shape

Postby Nicolette_Canlian_2L » Thu Dec 06, 2018 12:21 am

I believe its geometry comes about because of the lone pair on the iodine. If it were trigonal bipyramidal, there would not be any lone pairs on the central atom.

Raymond Ko 1H
Posts: 29
Joined: Fri Sep 28, 2018 12:19 am

Re: Molecular Shape

Postby Raymond Ko 1H » Thu Dec 06, 2018 12:30 am

The lone pair on the Iodine atom pushes the other atoms down, creating a square pyramidal structure. The structure for an AX5 molecule is trigonal bipyramidal, so removing one of the bonds and replacing it with a lone pair would result in repulsion.


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