Question

Which of the following compounds will not give Lassaignes test for nitrogen?

• A. $NH _{2} NH _{2}$
• B. $C _{6} H _{5} NHNH _{2}$
• C. $ PhN=NPh $
• D. $NH _{2} CONH _{2}$

Answer 1

Answer: (A)

Presence of carbon alongwith nitrogen is an essential condition for giving positive Lassaignes test for nitrogen.
Hence, $ NH_{2}\,.NH_{2} $ (due to absence of carbon) does not give Lassaignes test for nitrogen.