What can be inferred from the magnetic moment values of the following complex species ?`{:("Example","Magnetic",(BM)),(K_(4)[Mn(CN)_(6)),2.2),([Fe(H_(2)O)_(6)]^(2+),5.3),(K_(2)[MnCl_(4)],5.9):}`

Explanation

Magnetic moment `(mu)` is given as `mu=sqrt(n(n+2))`
For value n = 1, `mu=sqrt(1(1+2))=sqrt(3)=1.732`
For value n = 2, `mu=sqrt(2(2+2))=sqrt(8)=2.83`
For value n = 3, `mu=sqrt(3(3+2))=sqrt(15)=2.87`
For value n = 4, `mu=sqrt(4(4+2))=sqrt(24)=4.899`
For value n = 5, `mu=sqrt(5(5+2))=sqrt(35)=5.92`
(i) `K_(4)[Mn(CN)_(6)]`
For in transition metals, the magnetic moment is calculated from the spin-only formula. Therefore,b
`sqrt(n(n+2))=2.2`
We can see from the above calculation that the given value is closest to n=1. Also, in this complex, Mn is in the +2 oxidation state. This means that Mn has 5 electrons in the d-orbital.
Hence, we can say that `CN^(−)` is a strong field ligand that causes the pairing of electrons
(ii) `[Fe(H_(2)O)_(6)]^(2+)`
`sqrt(n(n+2))=5.3`
We can see from the above calculation that the given value is closest to n=4. Also, in this complex, Fe is in the +2 oxidation state. This means that Fe has 6 electrons in the d-orbital. Hence, we can say that `H_(2)O` is a weak field ligand and does not cause the pairing of electrons.
(iii) `K_(2)[MnCl_(4)]`
`sqrt(n(n+2))=5.9`
We can see from the above calculation that the given value is closest to n=5. Also, in this complex, Mn is in the +2 oxidation state. This means that Mn has 5 electrons in the d-orbital.
Hence, we can say that `Cl^(-)` is a weak field ligand and does not cause the pairing of electrons.