Question

It is difficult to test nitrogen by direct methods of testing. Suggest an indirect test by which nitrogen gas can be tested?

Answer 1

Hint :Nitrogen is a regularly used and referred to inert gas (high abundance & low cost). It does not react with other compounds due to its inert nature. As a result of its nonreactive nature, nitrogen gas is extremely difficult to detect.

Complete Step By Step Answer:
In elemental analysis, the sodium fusion test, also known as Lassaigne's test, is used to determine the presence of foreign elements such as halogens, nitrogen, and sulphur in an organic molecule. J. L. Lassaigne was the one who came up with the idea. The test includes "fusing" the sample with clean sodium metal after it has been heated to a high temperature. A wide range of methods have been described. The "fused" sample is submerged in water, and the resulting solution is subjected to the normal qualitative testing for the various ingredients. The organic chemicals are covalently bound to the halogens, nitrogen, and sulphur. The elements must be transformed into their ionic forms in order to be detected. The organic molecule is fused with sodium metal to accomplish this. The ionic chemicals generated during fusion are extracted in aqueous solution and recognised using basic chemical assays.
In a fusion tube, a little amount of organic material is fused with a little amount of sodium metal. The contents of the red hot fusion tube are then immersed in distilled water and cooked for a few minutes before being cooled and filtered. The mixture was then chilled and filtered. Sodium fusion extract (SFE) or Lassaigne's extract is the filtrate obtained. It is frequently alkaline in nature. A few drops of NaOH solution can be added to make it alkaline if it isn't already.
\[Na{\text{ }} + {\text{ }}C{\text{ }} + {\text{ }}N \to NaCN\].

Note :
Sodium fusion extract, also known as Lassaigne's extract, is the name of the extract. Any halogens, nitrogen, and sulphur will be transformed into inorganic sodium salts such as sodium halide (for halides), sodium cyanide (for nitrogen), sodium sulphide (for sulphur), and sodium thiocyanate (for sulphur) when an organic molecule is heated severely with sodium (for sulphur and nitrogen). With ferrous sulphate, the nitrogen is verified.