# Lassaigne's test for the detection of nitrogen fails in

(a) $H_2N.CONHNH_2.HCl$ (b) $H_2NNH_2.HCl$ (c) $H_2NCONH_2$ (d) $C_6H_5NHNH_2.HCl$

In the absence of carbon in the organic compound in Lassigne's test, NaCN is not formed as a product.

Answer: $H_2NNH_2.HCl$

As $H_2NHNH_2.HCl$ does not have any carbon, it does not respond to the Lassaigne's test.

answered Jan 24, 2014

option 2 is correct as compound does not have carbon
answered Jan 22, 2017

$NH_2-NH_2.HCl$
Some compound like hydrazine $(NH_2NH_2)$ although contain nitrogen, they do not respond lassaigne's test because they do not have any carbon & hence NaCN is not formed.
answered Nov 22, 2017