Why do textbooks have conflicting answers about the hybrid orbitals in H2S?

[ciubba]

I'm seeing conflicting answers among various textbooks. I would predict that it forms SP³ hybrid orbitals, and yet its bond angles are far from 109.5.

Edit: H2S, rather.

 

[Borek]

No hybridization at all and pure sp³ are just two ends of a continuum.

For some highly symmetrical molecules (say, CH₄) hybridization of the central atom is a pure sp³. But for some other molecules, like H₂S, what we observe is just some partial hybridization, in which bonds are not equivalent.

 

[DrDu]

Note also that hybridization is not a property of the molecule but entirely your personal choice of a convenient expression for the molecules wavefunction.
E.g. molecules like ethylene can equally well be described in terms of sp2+p or sp3 hybrids and water in terms of s+p or sp3 or even something intermediate.
In the case of H2S a description in terms of pure s and p orbitals makes probably more sense than the assumption of sp3 hybrid orbitals as the s and p orbitals in second row atoms differ considerably in size and energy.

 

[ciubba]

No hybridization at all and pure sp³ are just two ends of a continuum.

For some highly symmetrical molecules (say, CH₄) hybridization of the central atom is a pure sp³. But for some other molecules, like H₂S, what we observe is just some partial hybridization, in which bonds are not equivalent.

I see. How does one determine whether pure hybridization is a more appropriate model to describe orbital shape?

 

[PFuser1232]

What about HCl, are orbitals of chlorine hybridized in that case?

 

[Borek]

No need for that.