Do you know !!!
Detection of Nitrogen:
Take 2ml of lassaigne’s filtrate in a test tube and add a few drops of sodium hydroxide (NaOH) solution to it.
Also, Read the Preparation of Lassaigne’s solution
Now add a few ml of freshly prepared ferrous sulphate (FeSO4) solution to the test tube.
Boil the solution.
The sodium cyanide formed during the preparation of lassaigne’s solution is converted to sodium Ferrocyanide.
Add a few drops of FeCl3 solution to a test tube.
Finally, acidify it with concentrated HCl.
The appearance of blue or greenish-blue ( Prussian blue ) colour or ppt of ferric ferrocyanide proves the presence of nitrogen in the organic compound.
If a blood-red colour appeared instead of Prussian blue colour then it proves that both nitrogen and sulphur are present in an organic compound.