The Crystal Field Stabilisation energy of (i) [ CoF ₆]³⁻ and (ii) [ Fe ( H ₂ O )₆]³⁺ are ----- and ------- respectively.

Step-by-step solution

For the complex [ CoF ₆]³⁻ : The oxidation state of Co is +3 . The electronic configuration of Co ³⁺ is 3d^6 . Since F ^- is a weak field ligand, the complex is high-spin. The electrons are distributed in the t_ 2g and e_g orbitals as t_ 2g ^4 e_g^2 . CFSE = (-0.4 n_ t_ 2g + 0.6 n_ e_g ) ₀ CFSE = (-0.4 4 + 0.6 2) ₀ = (-1.6 + 1.2) ₀ = -0.4 ₀ For the complex [ Fe ( H ₂ O )₆]³⁺ : The oxidation state of Fe is +3 . The electronic configuration of Fe ³⁺ is 3d^5 . Since H ₂ O is a weak field ligand, the complex is high-sp