s-character

[Anna Castaneda 2E]

2F.15 in the textbook says that as the s-character of a hybrid orbital increases, the bond angle increases. Could anyone explain why?

[Natalie Keung 1D]

Think about the dominant character of the averages in each bond. A sp3 hybrid orbital has 1/4 s character and 3/4 p character. This hybrid has 109.5 degree bonds. A sp hybrid has 1/2 s character and 1/2 p character and 180 bond angles. This shows that when the hybrid s characters increase, so do the bond angles.

[Barbara Soliman 1G]

Take a look at the ratios. When it is sp, there is a 1:1 ratio. When it is sp3, there is a 1:2 ratio. So, the more p orbitals there are in the hybridization, the less s-character that is present. Hope this helps!