An octahedral complex of Fe ³⁺ is found to have a spin-only magnetic moment of approximately 1.73 B.M. The Crystal Field Stabilization Energy (CFSE) of this complex, ignoring the pairing energy, is:

Step-by-step solution

The spin-only magnetic moment is given by = n(n+2) B.M. Given 1.73 B.M. , which corresponds to 3 B.M. , we have n = 1 unpaired electron. The central metal ion is Fe ³⁺ , which has a 3 d ^5 electronic configuration. For an octahedral 3 d ^5 complex to have only 1 unpaired electron, it must be a low-spin complex formed in the presence of a strong field ligand. The electrons will pair up in the lower energy orbitals. The electronic configuration in the crystal field is t _ 2 g ^5 e _ g ^0 . The Crystal Field Stabiliza