Coordination compounds plays many important roles in animals and plants. The are essential in the storage and transport of oxygen as electrons transfer agents as catalysts and in photosynthesis Wide range of application in daily life takes place through formation of complexes Photographic fixing qualitative and quantitative analysis purification of water metallurgical extraction are some specific worth mentioning
The complex `[Fe(H_(2)O)_(5)NO]^(2+)` is formed in the brown ring test for nitrates when freshly prepared `FeSO_(4)` soultion is added to aqueous solution of `NO_(3)^(Θ)` followed by addition of conc. `H_(2)SO_(4)` Select correct statement about this complex
(a) Colour change is due to charge transfer
(b) It has iron in `+1` oxidation state and nitrosyl as `NO^(o+)`
(c ) It has magnetic moment of `3.87BM` confirming three unpaired electrons in Fe
(a) All the above are correct statements .

Options

A. Colour change is due to charge transfer .
B. It has iron in `+1` oxidation state and nitrosyl as `NO^(o+)` .
C. It has magnetic moment of `3.87BM` confirming three unpaired electrons in Fe .
D. In complex Fe has `d^(2)sp^(3)` hybridisation .

Answer

A, B, C

Explanation

(a) `Fe^(2+)` changes to brown -coloured ring complex
(b) `NOrarrNO^(o+)+e^(Θ)`
`Fe^(2+) + e^(Θ)rarrFe^(o+)`
`mu_(eff) = sqrt(n(n+2)) = sqrt15 = 3.87BM`
Thus (a),(b) and (c ) true
(d) `sp^(3)d^(2)` Hybridisation .