Explain the reason for the fusion of an organic compound with metallic sodium for testing nitrogen,sulphur,and halogens.

(N/A) Organic compounds contain elements like nitrogen,sulphur,and halogens in a covalent form.
These elements cannot be detected directly by standard chemical tests.
Fusion with metallic sodium converts these elements into their corresponding water-soluble ionic salts.
The reactions are as follows:
$Na + C + N \rightarrow NaCN$
$2Na + S \rightarrow Na_{2}S$
$Na + X \rightarrow NaX$ (where $X = Cl, Br, I$).
These ionic salts can then be easily detected using specific reagents.