Sodium nitrate
| Formula | NaNO3 |
| Chemical formula | NaNO3 |
| Density | 2.26 g/cm3 (20°C) |
| Molar mass | 84.99 g/mol |
| Bulk density | 1200 kg/m3 |
| CAS number | 7631-99-4 |
| HS Code | 31025090 |
| EC number | 231-554-3 |
| Storage | Without limitation |
| SDS | available |
| RTECS | WC5600000 |
| R phrase | R 8-22-36 |
| S phrase | S 22-24-41 |
| Odour | odourless |
| Form | Ssolid |
| Color | colourless |
| p H | 5.5 – 8.0 (50g/l 20°C) |
| Solubility in water | 874 g/l (20°C) |
| Solubility in ethanol | 8 g/l (20°C) |
| Melting point | 308 °C |
| Thermal decomposition | >380 °C |
| Assay | 99.0 – 100.5 | % | |
| Description | Conforms | ||
| Identification | Conforms | ||
| Solubility | Conforms | ||
| Clarity of solution | Conforms | ||
| p H | 5.5 – 8.3 | ||
| Total chlorine | ≤ | 0.2 | % |
| Nitrite | ≤ | 0.002 | % |
| Heavy metals | ≤ | 0.0005 | % |
| Loss on drying | ≤ | 2 | % |
Sodium nitrate is a white, odorless, crystalline solid that occurs naturally as a mineral known as nitratine. It is a highly soluble salt widely used in fertilizers, food preservation, and various industrial processes due to its oxidizing properties and nitrogen content.
🏭⚗️ Production
Sodium nitrate is produced both from natural mineral deposits and through synthetic processes. Commercially, it is often manufactured by neutralizing nitric acid with sodium carbonate or sodium hydroxide. Historically, large deposits in Chile were the primary source, but today, synthetic production dominates global supply. The final product is purified by crystallization.
🔬 Properties
The chemical formula of sodium nitrate is NaNO₃, with a molar mass of approximately 84.99 g/mol. It appears as a white crystalline solid, is odorless, and has a salty taste. It has a melting point of about 308 °C and decomposes above 380 °C, releasing oxygen and nitrogen oxides. Sodium nitrate is highly soluble in water and moderately soluble in alcohol. As an oxidizing agent, it can accelerate the combustion of combustible materials.
🧪 Applications
Sodium nitrate is primarily used as a nitrogen-rich fertilizer in agriculture. In the food industry, it serves as a preservative and curing agent, especially in meats, where it is designated as food additive E251. Industrially, it is used in the manufacture of explosives, fireworks, and glass, as well as in heat storage materials for solar energy systems. It also finds applications in metal treatment and as a corrosion inhibitor.
⚠️ Safety
Sodium nitrate is generally safe under controlled use but should be handled with caution due to its strong oxidizing properties. Contact with flammable or combustible materials can pose a fire risk. Inhalation or ingestion of large amounts may cause irritation to the respiratory or digestive systems and, in extreme cases, methemoglobinemia. Protective equipment should be used during handling, and it should be stored in a dry, cool place away from reducing agents, acids, and organic materials.
