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trigonal planar vs trigonal pyramidal

Posted: Sun Nov 17, 2019 4:32 pm
by Giovanni Anguiano-Gutierrez 3L
What's the difference between these two if the lewis structures look the same in shape?

Re: trigonal planar vs trigonal pyramidal

Posted: Sun Nov 17, 2019 4:33 pm
by chemboi
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

Re: trigonal planar vs trigonal pyramidal

Posted: Sun Nov 17, 2019 4:49 pm
by Harry Zhang 1B
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).

Re: trigonal planar vs trigonal pyramidal

Posted: Sun Nov 17, 2019 4:59 pm
by KarineKim2L
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.