99 Percentile Qs Bank for JEE MainChemistryp Block Elements (Group 15, 16, 17 & 18)
The complex [Fe(H 2 O) 5 NO] 2+ is formed in the brown ring test for nitrates when freshly prepared FeSO 4 solution is added to aqueous solution of NO 3 - followed by addition of conc. H 2 SO 4 . Select correct statement about this complex.
Options
- AColour change is due to charge transfer
- BIt has iron in +1 oxidate state and nitrosyl as NO +
- CIt has magnetic moment of 3.87 BM confirming three unpaired electrons in Fe
- DAll the above are correct statement
Correct answer
D. All the above are correct statement
Step-by-step solution
Fe 2+ changes to brown-coloured ring complex NO → NO + + e - Fe 2 + + e - → Fe + Magnetic moment = N N + 2 = 1 5 = 3.87 BM Thus, Colour change is due to charge transfer, It has iron in +1 oxidate state and nitrosyl as NO + and It has magnetic moment of 3.87 BM confirming three unpaired electrons in Fe are true.