Consider the following complex ions, P, Q and R. P = [FeF₆]3- , Q = [V(H₂O)₆]2+ and R = [Fe(H₂O)₆]2+ The correct order of the complex ions, according to their spin-only magnetic moment values (in BM) is

Number of unpaired electrons in P = Fe³⁺ = 5 Number of unpaired electrons in Q = V²⁺ = 3 Number of unpaired electrons in R= Fe²⁺ = 4 All the ligands mentioned here are weak field ligands, Hence, the number of the unpaired electrons will remains same as there will be no pairing of the electrons. μ= n(n+2)BM Hence, the correct answer is option (b).