For 17 it will be C.hydrazine doesn't give test
As elemental Nitrogen cannot be found.
And K2So4 or CuSO4 acts as catalyst .see here
@arush_kumar_singh 28 b why?
@Atul_v 17 please explain
Why doesn't hydrazine give but phenylhydrazine gives?
It's given in ncert for 17
Hydrazine does not have C atom therefore on fusing with sodium metal, it does not form any NaCN which is the primary requirement of Lassaigne’s test.
For 28 phenoxide ion is formed so I just made its e- in resonance