Bond Angles and Hybridization

[Bianca Barcelo 4I]

Why does the bond angle between two hybrid orbitals increase as the s-character of the hybrids is increased? (This question was from 4.43, 6th edition)

[ChathuriGunasekera1D]

So for sp, the bond angle is 180. We can say (sort of) that 50% of this is contributed from the s and 50% is contributed from the p (because sp is one half s and one half p). For sp2, the bond angle is 120. Now about 33% of the angle is from the s and 67% is from the p (sp2 is one third s and two thirds p). In this case, as s influence decreased (50% to 33%), the bond angle decreased (180 to 120). We can then say that as s character increases, the bond angle increases as well.

[Brian Hom 2F]

Basically, as we move from sp to sp2 to sp3 to etc, the bond angles are shrinking. sp has the greatest s-character since there is only one p and it has a bond angle of 180 while sp3 has a smaller s-character and has a bond angle of 109.5