In Lassaigne's test for the detection of halogens,the sodium fusion extract is first boiled with concentrated nitric acid. This is

What can be inferred if a blood-red color is obtained in the Lassaigne's test?

In which of the following compounds will nitrogen not be detected by the Lassaigne test?

Beilstein test is used for the detection of which one of the following elements?

Given below are two statements :
Statement $I :$ In Lassaigne's test,the covalent organic molecules are transformed into ionic compounds.
Statement $II :$ The sodium fusion extract of an organic compound having $N$ and $S$ gives prussian blue colour with $FeSO_4$ and $FeCl_3$.
In the light of the above statements,choose the correct answer from the options given below.

Which compound is responsible for the formation of a blue precipitate when ferric ions react with a Lassaigne's extract or potassium ferrocyanide solution?