When the Lassaigne's extract of a sulfur-containing compound is treated with sodium nitroprusside,what color is obtained?

Lassaigne's test is not used for the detection of the element . . . . . . in the organic compound.

The violet color obtained in the Lassaigne's test for a sulfur-containing compound is due to the formation of which species?

Which of the following compounds would give the following set of qualitative analysis?
$(i)$ Fehling's Test : Positive
$(ii)$ $Na$ fusion extract upon treatment with sodium nitroprusside gives a blood red colour.

The Beilstein test is used for the detection of:

An organic compound $A$ is oxidized with $Na_2O_2$ followed by boiling with $HNO_3$. The resultant solution is then treated with ammonium molybdate to yield a yellow precipitate. Based on the above observation,the element present in the given compound is: