Question

The compound formed in the positive test for nitrogen with the Lassaigne solution of an organic compound is

• A. $F{e}_4{[Fe{(CN)}_6]}_3$
• B. $N{a}_3[Fe{(CN)}_6]$
• C. $Fe{(CN)}_3$
• D. $N{a}_4[Fe{(CN)}_{5}NOS]$

Answer 1

Answer: (A)

If nitrogen is present in organic compound then sodium extract contains $N{a}_4[Fe{(CN)}_6]$ . $Na+C+N\stackrel{fuse}{\to }NaCN$ $FeS{O}_4+6NaCN\to \underset{(A)}{N{a}_4[fe{(CN)}_6]}+N{a}_{2}S{O}_4$ A changes to Prussian blue $F{e}_4{[Fe{(CN)}_6]}_3$ on reaction with $FeC{l}_3$ . $4FeC{l}_3+3N{a}_4[Fe{(CN)}_6]\to$ $F{e}_4{[Fe{(CN)}_6]}_3+12NaCl$