The fusion of sodium with an organic compound containing nitrogen gives mainly:

Assertion : During the test for nitrogen with Lassaigne's extract,on adding $FeCl_3$ solution,sometimes a blood-red coloration is obtained.
Reason : Sulphur is also present along with nitrogen in the organic compound.

Sodium fusion extract of which compound gives Prussian blue colour with $FeSO_4$?

Lassaigne's test for the detection of nitrogen fails in

Why is it necessary to use acetic acid and not sulphuric acid for acidification of sodium extract for testing sulphur by lead acetate test?

Assertion: Potassium can be used in the Lassaigne test.
Reason: Potassium reacts vigorously.