Sodium azide (NaN₃) is an inorganic compound, also known as sodium trinitride. It exists in the form of white hexagonal crystals, which are tasteless, odorless, and non-hygroscopic. Sodium azide is highly toxic, insoluble in ether, slightly soluble in ethanol, but soluble in liquid ammonia and water.

Uses of Sodium Azide 

1. Chemical synthesis: Sodium azide is widely used as a chemical reagent for the synthesis of other azide compounds or azide salts, such as lead azide, silver azide, etc.

2. Preservative for photographic emulsions: In the photographic industry, sodium azide can be used as a preservative for photographic emulsions to prolong the service life of emulsions.

3. Blood culture medium components: In the field of microbiology, sodium azide can be used as a component of blood culture media for the cultivation of specific microorganisms.

4. Analytical chemistry reagents: Sodium azide is used in analytical chemistry as a reagent for the detection of sulfides and thiocyanates.

5. Organic synthesis: In organic chemistry, sodium azide is used as a raw material to make a variety of organic compounds.

6. Automotive airbags: Sodium azide plays a key role in automotive airbag systems, quickly releasing nitrogen and inflating airbags in the event of a car accident.

7. Pharmaceutical raw materials: In the pharmaceutical industry, sodium azide is used in the synthesis of certain drugs, especially the synthesis of antibiotic cephalosporins.