Question

Explain the formation of [CO(NH₃)₆]³⁺ complex ions with respect to the type of hybridisation.

Answer 1

The complex ion [CO(NH₃)₆]³⁺ is an example of a coordination complex where cobalt (CO³⁺) is the central metal ion and six NH₃ ligands surround it.

• The oxidation state of CO in [CO(NH₃)₆]³⁺ is +3.
• The electronic configuration of CO (Z = 27) is [Ar] 3d⁷ 4s².
• CO³⁺ has the configuration [Ar] 3d⁶.
• Since NH₃ is a strong field ligand, it causes pairing of electrons in the 3d orbitals.
• This leads to d²sp³ hybridization, forming an octahedral geometry.