The compound formed in the positive test for nitrogen with the Lassaigne solution of an organic compound is
(a) Fe4[Fe(CN)6]3
(b) Na3[Fe(CN)6]
(c) Fe(CN)3
(d) Na4 [Fe(CN)5NOS.
(a) : 3Na4[Fe(CN)6] + 4Fe3+ → Fe4 [Fe(CN)6]3 + 12Na+ Prussian blue
