BITSAT2018ChemistryGeneral Organic ChemistryActual
Which of the following compound will give blood red colour while doing the Lassaigne's test for N .
Options
- ANH 2 2 C = O
- BH 2 N C 6 H 4 SO 3 H
- CC 6 H 5 SO 3 H
- DCHCl 3
Correct answer
B. H 2 N C 6 H 4 SO 3 H
Step-by-step solution
When nitrogen and sulphur both are present in the organic compound, they combine during fusion to form sodium thiocyanate (sulphocyanide). Thus, the compounds containing both N and S give blood red colour in Lassaigne's test due to the formation of Fe SCN 2 . Thus, H 2 N C 6 H 4 SO 3 H gives blood red colour in Lassaigne's test of nitrogen.