Question

Co²⁺ is easily oxidised to Co³⁺ in the presence of a strong ligand. [At. No. of Co = 27]

Answer 1

When strong field ligands are present, Co³⁺ can be converted to Co³⁺. Strong field ligands, such as CO or CN⁻ (cyanide), produce a strong ligand field that stabilizes the metal ion’s higher oxidation state. Because strong field ligands significantly split the d-orbitals, favoring the +3 oxidation state, this stabilization takes place.