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Question #44587
The Question
An aqueous solution contains a homoleptic coordination complex anion (where = oxalate), which has been resolved into its pure dextrorotatory enantiomer at 298 K. The central transition metal belongs to the 3d series and possesses a electronic configuration in its +3 oxidation state. Based on Crystal Field Theory (CFT), what is the spin-only magnetic moment () of this optically active isomer, and its corresponding Crystal Field Stabilization Energy (CFSE) in terms of ?
Options
- A.
- B.
- C.
- D.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Exception_Exposure
Learn to identify edge cases and boundary exceptions that JEE examiners hide in math problems.
Concepts Behind This Question
Spin-Only Magnetic Moment|Optical Isomerism Logic|Crystal Field Splitting (Octahedral)
Why This Question Is Tricky
Common Mistakes
This problem tests a critical exception in Coordination Chemistry regarding the Spectrochemical Series.
Students often rigidly memorize that oxygen-donor ligands like oxalate are weak-field and default to high-spin configurations (leading to the trap answer of 4.90 BM).
The hidden variable is the synergistic effect of the metal's high oxidation state (+3) and the ligand's chelating nature.
For Co(III), these factors increase the crystal field splitting energy () so much that it overcomes the pairing energy (), resulting in an anomalous low-spin, diamagnetic complex despite the presence of a traditionally 'weak-field' ligand.
The mention of optical isomerism serves as a cognitive distractor, ensuring students don't dismiss the octahedral geometry but potentially reinforcing a false confidence in a standard weak-field VBT assumption.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Coordination Compounds - Class 12 |
| Concept | Spin-Only Magnetic Moment |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |