Which of the following compounds dues not show lassaigne's test for nitrogen ?

(a) Urea

(b) Hydrazine

(c) Phenylhydrazine

(d) Azobenzene

Hydrazine $(NH_2NH_2)$ does not contain and hence no fusion with Na metal , it cannot form $NaCN$ .
Therefore , hydrazine does not show lassaigne's test,
Hence b is the correct answer.
answered Mar 3, 2014 by

c option must be the corrrect answer
answered Nov 26, 2016