Bond Angles for Angular, T-shaped, etc.

[Rachael_1H]

Hello,

How do we determine the bond angles for angular, trigonal pyramidal, t-shaped, see-saw, and square pyramidal molecules? They are not written in the book on page 109.

[Chem_Mod]

Just try and keep in mind the spatial orientation of the molecules and the shapes that are present. In the illustration below, it is a seesaw molecular shape. The two chlorines and the lone pair are all on the same axis in a circular shape. Thats how we can determine the bond angle is around 120. The top and bottom chlorines are in a linear shape. Therefore, they are 180 from each other and 90 from each of the other two chlorines. If you can picture this, you can derive the angles this way. If not, you would just have to memorize them.

[Chem_Mod]

[Reine Nakamura 1C]

For T-shaped, would the bond angles be slightly less than 90 because of the 2 lone pairs pushing down on those that are bonded?

[Rachael_1H]

Yes the bond angles would be slightly less than 90 degrees because of the two lone paires