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. (a) `QltRltP`
B. (b) `RltQltP`
C. (c) `RltPltQ`
D. (d) `QltPltR`

Answer

A

Explanation

`underset((P))[FeF_6]^(3-)rarrFe^(3+)rarrd^5` configuration.
`F^(-)` is weak field ligand
Unpaired electrons `=5`, `:. mu=sqrt(5(5+2))=5.95` B.M.
`underset((Q))[V(H_2O)_6]^(2+)rarrV^(+2)rarrd^3` configuration,
`H_2O` is weak field ligand
Unpaired electron `=3`, `:. muimpliessqrt(3(3+2))=3.87 B.M.`
`underset((R))[Fe(H_2O)_6]^(2+)rarrFe^(+2)rarrd^6` configuration,
`H_2O` is weak field ligand
Unpaired electron`=4`, `:. mu=sqrt(4(4+2))=4.90 B.M.`
Therefore only spin magnetic moment `(mu)=sqrt(n(n+2))`
B.M. (n=unpaired electron)
So, `mu` of `PgtRgtQ`.