The coordination numbers of Co and Al in [Co(Cl)(en)₂]Cl and K₃[Al(C₂O₄)₃], respectively, are : (en = ethane-1, 2-diamine)

The compound used in the treatment of lead poisoning is :

The complex ion that will lose its crystal field stabilization energy upon oxidation of its metal to +3 state is :

Complete removal of both the axial ligands (along the z-axis) from an octahedral complex leads to which of the following splitting patterns? (relative orbital energies not on scale).