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

Solution :
Prussian blue $$F{e_4}{\left[ {Fe{{\left( {CN} \right)}_6}} \right]_3}$$   is formed in lassaigne test for nitrogen.
$$3N{a_4}\left[ {Fe{{\left( {CN} \right)}_6}} \right] + 4F{e^{3 + }} \to \mathop {F{e_4}{{\left[ {Fe{{\left( {CN} \right)}_4}} \right]}_6} + 12N{a^ + }}\limits_{{\text{Prussian}}\,{\text{blue}}} $$