The correct order of the following complexes in terms of their crystal field stabilization energies is :

Step-by-step solution

Crystal field splitting energy ( ) charge or oxidation state of central metal atom. Crystal field splitting energy ( ) Field strength of ligand (and chelation) Crystal field stabilisation energy (CFSE) = [-0.4 t _ g _g . +0.6 eg] _ (for octahedral) For, aligned & [ Co ( en )₃ ]³⁺: Co ³⁺: t _ 2 ~g ^6 eg ^0 ; CFSE =-2.4 ( ₀ )₁ & [ Co ( NH ₃ )₆ ]³⁺: Co ³⁺: t _ 2 ~g ^6 eg ^0 ; CFSE =-2.4 ( ₀ )₂ & [ Co ( NH ₃ )₆ ]²⁺: Co ²⁺: t _ 2 g ^5 eg ^2 ; CFSE =-0.8 ( ₀ )₃ & [ Co ( NH ₃ )₄ ]²⁺: Co ²⁺: e ^4 t ₂^3 ; CFSE =-1.2 _ t & (