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T shaped

Posted: Mon Nov 26, 2018 5:22 pm
by Peter Nguyen 2I
Why does AX3E2 make a T-shape and doesn't form a trigonal planar shape?

Re: T shaped

Posted: Mon Nov 26, 2018 5:25 pm
by Rehan Chinoy 1K
I believe it has to do with the bond angles. The two lone pairs cause the angles between the central atom and each ligand to be less than 90 degrees, whereas the angles between the ligands and the central atom in a trigonal planar molecule are 120 degrees.

Re: T shaped

Posted: Mon Nov 26, 2018 11:05 pm
by Elena Maneffa 1E
AX3E2 means that an atom is bonded to 3 other atoms and also has 2 lone pairs.

If it had just one lone pair it would be trigonal pyramidal but because of the second lone pair, it changes the angles and is now considered to be T-shaped.

Re: T shaped

Posted: Tue Nov 27, 2018 11:47 am
by Matthew Mar 1J
The T-shape is a planar shape, so you can think of it almost like a trigonal planar shape that just has two lone pairs which push the atoms closer together to a 90 degree angle instead of the 120 degree angle.

Re: T shaped

Posted: Tue Nov 27, 2018 1:16 pm
by Mayaal_Khan_4H
AX3E2 means that the central atom is bonded to 3 atoms and has 2 lone pairs, since there are 2 lone pairs instead of 1, the bond angles change and therefore the shape changes from trigonal planar to T-shape

Re: T shaped

Posted: Tue Nov 27, 2018 1:29 pm
by Adrienne_4F
There is repulsion due to the two lone pairs, therefore they will push the atoms closer together, making a T shape rather than a trigonal planar.

Re: T shaped

Posted: Tue Nov 27, 2018 1:34 pm
by 905096106
It is not trigonal planar because of the additional two lone pairs. These distort the shape and make the bond angles smaller so the 120 degree angle found on trigonal planar shapes is not obtained.