Question

Draw the structure and write the hybridisation state of the central atom of the following specie: 

[Co(NH₃)₆]³⁺

Answer 1

1. The central atom is Cobalt (Co) in the +3 oxidation state, coordinated to six ammonia (NH₃) ligands.
2. The complex has an octahedral geometry because of the six ligands surrounding the central metal ion, each bonding with a lone pair of electrons.
   
3. The central Co³⁺ ion undergoes d²sp³ hybridisation.
4. The hybridisation involves two d orbitals, one s orbital, and three p orbitals from cobalt, which combine to form six hybrid orbitals, each overlapping with a lone pair of electrons from each NH₃ ligand.
5. The geometry resulting from this hybridisation is octahedral.