NEETChemistryCoordination Compounds
What is the correct crystal field electronic configuration and the spin-only magnetic moment of the central metal ion in the complex [CoF₆]³⁻ ?
Options
- At_ 2g ^6 e_g^0 and 0 BM
- Bt_ 2g ^4 e_g^2 and 0 BM
- Ct_ 2g ^5 e_g^1 and 2.83 BM
- Dt_ 2g ^4 e_g^2 and 4.90 BM
Correct answer
D. t_ 2g ^4 e_g^2 and 4.90 BM
Step-by-step solution
In the complex [CoF₆]³⁻ , the oxidation state of Co is +3 . The electronic configuration of Co atom is [Ar] 3d^7 4s^2 . Therefore, the Co³⁺ ion has a 3d^6 configuration. The complex is octahedral (coordination number 6 ). According to the spectrochemical series, F^- is a weak field ligand, meaning the crystal field splitting energy is less than the pairing energy ( _o For a d^6 ion in a weak octahedral field, the first three electrons singly occupy the lower energy t_ 2g orbitals, the next two singly occupy the hig