An octahedral complex of Fe ²⁺ has a spin-only magnetic moment of 0 BM. The Crystal Field Stabilization Energy (CFSE) for this complex, ignoring the pairing energy, is:

Step-by-step solution

The central metal ion is Fe ²⁺ , which has an electronic configuration of [ Ar ] 3d^6 . The spin-only magnetic moment is given as 0 BM. The formula for magnetic moment is = n(n+2) BM, where n is the number of unpaired electrons. Since = 0 , the number of unpaired electrons n = 0 . For an octahedral d^6 complex to have zero unpaired electrons, it must be a low-spin complex where all electrons are paired in the lower energy t_ 2g orbitals. The electronic configuration in the crystal field is t_ 2g ^6 e_g^0 . The Crys