Question

detect the presence of nitrogen atom in a given organic compound o

Answer 1

The carbon and nitrogen present in the organic compound on fusion with sodium metal gives sodium cyanide (NaCN) soluble in water. This is converted in to sodium ferrocyanide by the addition of sufficient quantity of ferrous sulphate. Ferric ions generated during the process react with ferrocyanide to form prussian blue precipitate of ferric ferrocyanide.

 

Na + C + N → NaCN

 

6NaCN + FeSO4 → Na4[Fe(CN)6] + Na2SO4

                               Sodium ferrocyanide

 

 Na4[Fe(CN)6] + Fe3+ → Fe4[Fe(CN)6]3

                                        Ferric ferrocyanide