The Lassaigne's solution when heated with ferrous sulphate and acidified with sulphuric acid gave intense blue colour indicating the presence of nitrogen. The blue colour is due to formation of:

Options

A. (a)`Na_(4)[Fe(CN)_(6)]`
B. (b)`Fe_(3)[Fe(CN)_(6)]_(2)`
C. (c )`Fe_(2)[Fe(CN)_(6)]`
D. (d)`Fe_(4)[Fe(CN)_(6)]_(3)`

Answer

D

Explanation

`4FE^(3+)+3Na_(4)[Fe(CN)_(6)] rarr 12 Na^(+)+Fe_(4)underset("blue colour")([Fe(CN)_(6)]_(3))`