Correct Answer - Option 2 : V
2+ > Cr
2+ > Ru
3+ > Fe
2+
Concept:
The spin magnetic moment is directly proportional to the number of unpaired electrons.
The number of unpaired electrons for [V(CN)6]4- is 3
The number of unpaired electrons for [Fe(CN)6]4- is 0
The number of unpaired electrons for [Ru(NH3)6]3+ is 1
The number of unpaired electrons for [Cr(NH3)6]2+ is 2
The correct order of the spin-only magnetic moment of metal ions is:
V2+ > Cr2+ > Ru3+ > Fe2+