Q. The Prussian blue colour obtained during the test of nitrogen by Lassaigne;s test is due to the formation of
A) $Fe\left\lbrack Fe(CN)_{6} \right\rbrack_{3}$
B) ${Na}_{4}\lbrack Fe(CN)_{6}\rbrack$
C) ${Fe}_{3}\left\lbrack Fe(CN)_{6} \right\rbrack_{4}$
D) ${Fe}_{2}\lbrack Fe(CN)_{6}\rbrack$
Explanation
(a)
The treatment with $FeCl_{3}$ yield ferric ferrocyanide which has bulish green or prussian blue colouration
$3{Na}_{4}\left\lbrack Fe(CN)_{6} \right\rbrack + 4FeCl_{3} \rightarrow Fe_{4}\left\lbrack Fe(CN)_{6} \right\rbrack_{3}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.