Consider the follwing complexes ion `P,Q` and `R`
`P =[FeF_(6)]^(3-), Q=[V(H_(2)O)_(6)]^(2+)` and `R=[Fe(H_(2)O)_(6)]^(2+)`
The correct order of the complex ions, according to their spin only magnetic moment values (inBM) is .

Options

A. `R lt Q lt P`
B. `Q lt R lt P`
C. `R lt P lt Q`
D. `Q lt P lt R`

Answer

B

Explanation

P = `|FeF_(6)|^(3-)` has `Fe^(3+)` , i.e., `3d^(5)` (5 unpaired electrons)
Q = `|V(H_(2)O)_(6)|^(2+)` has `V^(2+)` , i.e., `3d^(3)` (3unpaired electrons )
R = `|Fe((H_(2)O)_(6)|^(2+)` has `Fe^(2+)` i.e., `3d^(6)` (4 unpaired electrons)
`:.` the order of spin only magnetic moment is `Q lt R lt P` .