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Aedra Li 3H
Posts: 40
Joined: Fri Aug 30, 2019 12:17 am


Postby Aedra Li 3H » Wed Nov 13, 2019 11:20 pm

Problem 2E9 asks to determine the shape of an ICl3 molecule. When I drew the Lewis Structure, I had 3 bonding pairs and 2 lone pairs so I assumed the shape would be a trigonal bipyramidal. However, in the solution manual it says that it has a T shape. Why is this the case?

Joelle 3L
Posts: 50
Joined: Sat Jul 20, 2019 12:16 am

Re: 2E9

Postby Joelle 3L » Wed Nov 13, 2019 11:24 pm

Trigonal bipyramidal does have does have five groups of electrons. However, it does not have any lone pairs like the ones you drew in the lewis structure. A structure with five electron groups and 2 lone pairs is called T shape. You should look at the number of lone pairs when naming.

Brynne Burrows 3K
Posts: 52
Joined: Thu Jul 25, 2019 12:16 am

Re: 2E9

Postby Brynne Burrows 3K » Wed Nov 13, 2019 11:52 pm

The lone pair counts as an area of electron density which moves the atoms also bonded to the central atom as far away from each other as possible, which changes the molecule's shape.

Katie Kyan 2K
Posts: 106
Joined: Fri Aug 09, 2019 12:16 am
Been upvoted: 1 time

Re: 2E9

Postby Katie Kyan 2K » Wed Nov 13, 2019 11:53 pm

A structure that is trigonal bipyramidal has 5 bonding pairs of electrons around the central atom. However, a structure with 3 bonding pairs and 2 lone pairs is T-Shaped as the lone pairs change the bond angle and orientation of the molecule.

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