CHEMISTRY COMMUNITY

For question 43, it gives you that the bond angle of the sp^3 hybridized atom is 109.5 degrees and the bond angle of an sp^2 hybridized atom is 120 degrees.
The question asks if you expect the bond angle between two hybrid orbitals to increase or decrease as the s-character of the hybrids is increased? I know that the answer from the back of the books says that as the s-characters increase, the bond angle between two hybrid orbitals increases. Could someone please explain why, thank you.

S-character corresponds to how much a sigma bond contributes to the hybridization of an atom. For example, an atom with sp hybridization is 50% s-character and 50% p-character, sp2 would be 33% s-character and 66% p-character, sp3 would be 25% s-character and 75% p-character. When looking at the bond angles of these different hybridizations, sp hybridization is 180 degrees, sp2 is 120 degrees, and sp3 has 109.5 degree bond angles. Therefore, we can see that atoms with greater s-character have larger bond angles between orbitals (in order keep them as far apart from each other as possible), and as s-character decreases, the bond angles decrease as well. Hope this helps a bit!