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VSEPR Angles

Posted: Sun Nov 17, 2019 6:36 pm
by DTingey_1C
Is it necessary that we know the exact angles created by each of the different molecular shapes?

Re: VSEPR Angles

Posted: Sun Nov 17, 2019 6:42 pm
by zoedfinch1K
I think for the general shapes we are expected to know the bond angles but for cases where there are lone pairs on the central atom, we just need to know what the impact on the original bond angle would be.

Re: VSEPR Angles

Posted: Sun Nov 17, 2019 7:00 pm
by RasikaObla_4I
We should know the bond angles for the shapes that do not have lone pairs because the angles are constant. However, for the shapes with lone pairs, we need to know that the bond angles for trigonal pyramidal are less than 109.5 degrees.

Re: VSEPR Angles

Posted: Sun Nov 17, 2019 7:21 pm
by Bradley Whitworth 4B
Usually for VSEPR exact angles for everything is not expected. You should know the basic ones like 180 degrees, 120 degrees, and 109.5 degrees and you should know how lone pairs affect bonds which would be indicated by writing something like <109.5 degrees for example.

Re: VSEPR Angles

Posted: Sun Nov 17, 2019 7:24 pm
by Jordan Ziegler 2J
A followup question:

How do we determine if the bond angles are greater than or less than 109.5 degrees (or 90 degrees or 120 degrees)?

Do lone pairs repel more than bonding sites?