Lassaigne’s Solution(Sodium Extract):
Lassaigne’s solution or sodium fusion extract should be prepared to detect Nitrogen, Sulphur and halogens in the given organic compound.
Following is the list of materials required for the preparation of lassaigne’s solution.
- Sodium metal
- Distilled water
- Organic compound
- Test tube
- Fusion tube
- China dish
- Wire gauze
- Tripod stand’
- Filter paper
- Glass rod
- Bunsen burner
Take a small piece of dry sodium metal in a fusion tube.
Heat the fusion tube gently on the Bunsen burner to melt sodium metal.
Add a small amount of organic compound to a fusion tube.
Heat it first gently & then strongly the tube becomes red hot.
Break this fusion tube into a china dish containing 20cm3 of distilled water.
Mix ,boil & filter the solution .
This filtrate is called Lassaigne’s solution or sodium extract
Then divide the filtrate (Lassaigne’s solution ) into three parts to test the presence of N, S & halogens.
It is based upon the fact that when an organic compound containing nitrogen, sulphur and halogen is strongly heated with metallic sodium, its nitrogen converts to ionic NaCN (sodium cyanide), sulphur to ionic NaS (sodium sulphide) and halogen to ionic NaX (sodium halide) if they are present.