Nitrogen, sulphur and phosphorus present in organic compounds are detected by the formation of which of the following coloured substances respectively.

Options

A. `underset("Prussian blue")(Fe_(4)[Fe(CN)_(6)]_(3)), underset("Violet")([Fe(CN)_(5)NOS]^(-4)), underset("Yellow")((NH_(4))_(3)PO_(4)*12MoO_(3))`
B. `underset("Prussian blue")(Fe_(4)[Fe(CN)_(6)]_(3)), underset("Blood red")([Fe(SCN)]^(2+)), underset("Violet")((NH_(4))_(3)PO_(4)*12MoO_(3))`
C. `underset("Blue")([Fe(CN)_(6)]^(4-)), underset("Blood red")([Fe(SCN)]^(2+)), underset("Yellow")((NH_(4))_(3)PO_(4)*12MoO_(3))`
D. `underset("Blue")([Fe(CN)_(6)]^(4-)), underset("Violet")([Fe(CN)_(5)NOS]^(-4)), underset("Black")((NH_(4))_(3)PO_(4)*12MoO_(3))`

Answer

A

Explanation

Formation of the coloured substances :
(i) `Fe_(4)[Fe(CN)_(6)]_(3)` - Prussian blue (for nitrogen)
(ii) `[Fe(CN)_(5)NOS]^(4-)` - Violet (foro sulphur)
(iii) `(NH_(4))(3)PO_(4)*12MoO_(3)` - Yellow (for phosphorus)