trigonal planar vs trigonal pyramidal

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

Moderators: Chem_Mod, Chem_Admin

Giovanni Anguiano-Gutierrez 3L
Posts: 52
Joined: Thu Jul 25, 2019 12:17 am

trigonal planar vs trigonal pyramidal

Postby Giovanni Anguiano-Gutierrez 3L » Sun Nov 17, 2019 4:32 pm

What's the difference between these two if the lewis structures look the same in shape?

chemboi
Posts: 101
Joined: Sat Jul 20, 2019 12:16 am

Re: trigonal planar vs trigonal pyramidal

Postby chemboi » Sun Nov 17, 2019 4:33 pm

The lewis structures should not look the same. trigonal planar lewis structure will have a central atom with 3 regions of electron density, whereas trigonal pyramidal has 4 regions: 3 bonds and 1 lone pair

Harry Zhang 1B
Posts: 101
Joined: Sat Sep 14, 2019 12:16 am

Re: trigonal planar vs trigonal pyramidal

Postby Harry Zhang 1B » Sun Nov 17, 2019 4:49 pm

The lewis structures look the same because you can only draw them in a two-dimensional space but the VSEPR model depicts the shape in a three-dimensional space and illustrates the effect of repulsion by a lone pair, which results in a different shape and is not trigonal planar(has no lone pair).

KarineKim2L
Posts: 100
Joined: Fri Aug 30, 2019 12:16 am

Re: trigonal planar vs trigonal pyramidal

Postby KarineKim2L » Sun Nov 17, 2019 4:59 pm

Although trigonal planar and trigonal pyramid both result when 3 atoms are attached to the central atom, trigonal pyramid requires a lone pair on the central atom, while trigonal planar does not. In other words, trigonal planar has 3 regions of electron density, while trigonal pyramid has 4.


Return to “Determining Molecular Shape (VSEPR)”

Who is online

Users browsing this forum: No registered users and 3 guests