Which of the following organic compounds will successfully yield a positive test for nitrogen when s — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

Lassaigne's test for nitrogen requires both carbon and nitrogen in the molecule to form the detectable $CN^-$ ion during fusion with sodium. Urea, Phenylhydrazine, and Pyridine possess both elements. Hydrazine lacks carbon and will not form $NaCN$, thus giving a negative result.