CHEMISTRY COMMUNITY

Perhaps this isn't relevant to what we need to know for the final but for coordination compounds, say [NiCl2(NH3)4], which orbitals (hybridized or unhybridized) do the chloride and ammonia molecules bind to on the nickel atom? Since they are all coordinate covalent bonds, I would assume the orbitals aren't hybridized since the nickel isn't providing any electrons to form the bond.

We use the hybridization model for the p-block elements which applies to the ligands.
For example the nitrogen atom in NH₃ is sp³ hybridized.

The bonding model for the transition metal d-block elements requires molecular orbital theory or ligand field theory (which is covered in more specialized inorganic courses).