Introduction:
The sodium fusion test is a chemical test used to identify the presence of certain functional groups in organic compounds. It involves heating the organic compound with metallic sodium, which leads to the formation of various sodium salts. By analyzing the properties of these salts, we can determine the functional groups present in the original organic compound.

Explanation:
In the sodium fusion test, the nitrogen of the organic compound is converted into sodium cyanide (NaCN). This conversion occurs due to the reaction between the nitrogen in the organic compound and the sodium metal.

Reaction:
R-N + 2Na ⟶ R-Na + Na-Na ⟶ R-Na + NaCN

Reason for the Conversion:
The reaction occurs because of the high reactivity of sodium metal. Sodium readily donates an electron to the nitrogen atom, resulting in the formation of a sodium salt. The remaining sodium atom combines with another sodium atom to form sodium metal.

Formation of Sodium Cyanide:
Sodium cyanide (NaCN) is formed when the nitrogen in the organic compound reacts with sodium. Sodium cyanide is a colorless salt with a bitter almond odor. It is highly toxic and can release toxic hydrogen cyanide gas when it comes into contact with acids or is heated.

Other Sodium Salts:
Although sodium cyanide is the main product formed in the sodium fusion test, other sodium salts can also be generated depending on the functional groups present in the organic compound. For example:
- If the organic compound contains a carboxylic acid group, sodium carboxylate salts (sodium salts of carboxylic acids) will be formed.
- If the organic compound contains a phenol group, sodium phenoxide salts (sodium salts of phenols) will be formed.
- If the organic compound contains an amine group, sodium amide salts (sodium salts of amines) will be formed.

Conclusion:
In the sodium fusion test, the nitrogen of the organic compound is converted into sodium cyanide (NaCN). This conversion occurs due to the reaction between the nitrogen and sodium metal. By analyzing the properties of the resulting sodium salts, we can determine the functional groups present in the original organic compound.