Q. In Lassaigne’s test, a blue colour is obtained if the organic compound contains nitrogen. The blue colour is due to
A) $K_{4}\left\lbrack Fe(CN)_{6} \right\rbrack$
B) $Fe_{4}\left\lbrack Fe(CN)_{6} \right\rbrack_{3}$
C) $Na_{3}\lbrack Fe(CN)_{6}\rbrack$
D) ${Cu}_{2}\lbrack Fe(CN)_{6}\rbrack$
Explanation
(b)
In the Lassaigne’s test, a blue colour is obtained if the organic compound contains nitrogen. The blue colour is due to ferri-ferro cyanide $i.e.,$ $Fe_{4}\left\lbrack Fe(CN)_{6} \right\rbrack_{3}.$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.