Q.

Which of the following nitrogen containing compound does not give Lassaigne’s test              [2024]

1 Glycine  
2 Hydrazine  
3 Phenyl hydrazine  
4 Urea  

Ans.

(2)

In Lassaigne's test for nitrogen, NaCN is formed in sodium fusion extract, which is then tested further. Hydrazine (NH2-NH2) does not contain carbon hence NaCN cannot be formed in sodium fusion extract. So hydrazine does not give Lassaigne 's test for nitrogen.