The magnetic moment of [FeF₆]3− is approximately: (Fe atomic number = 26)
Fe₃+ (d5) in [FeF₆]3− (octahedral) with weak field F− is high spin (5 unpaired electrons). Magnetic moment = √[5(5+2)] = √35 ≈ 5.92 BM.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Colour and Magnetic Properties and Stability and Importance