Lassaigne's test for the detection of `N` fails in `:`

Options

A. `NH_(4)CONHNH_(2)`
B. `NH_(2)NH_(2)*HCl`
C. `NH_(2)CONH_(2)`
D. `C_(6)H_(5)NHNH_(2)*HCl`

Answer

B

Explanation

Lassaigne's test is given by only those compounds which contain both carbon and nitrogen . When compound containing C and N heated with sodium , then it form NaCN which is easily detected by `FeCl_(3)`
Or
Some compounds live hydrazine `( NH_(2) * NH_(2))` although contain nitrogen but they do not respond Lassaigne's test because they do not have any carbon and hence , NaCN is not formed .