Sodium nitrite
| Properties | |
| Chemical formula | NaNO3 |
| Molar mass | 84.9947 g/mol |
| Appearance | White powder |
| Density | 2.257 g/cm3, solid |
| Melting point | 308 °C (586 °F; 581 K) |
| Boiling point | 380 °C (716 °F; 653 K) decomposes |
| Solubility in water | 73 g/100 mL (0 °C) 91.2 g/100 mL (25 °C) 180 g/100 mL (100 °C) |
| Solubility | very soluble in ammonia, hydrazine soluble in alcohol slightly soluble in pyridine insoluble in acetone |
Sodium nitrite (NaNO2) is an inorganic salt that is generated by nitrite ions and sodium ions’ reaction. Sodium nitrite is easily hydrolyzing and soluble in water and liquid ammonia. Its aqueous solution is alkaline, the PH is about 9; and it is slightly soluble in organic solvents such as ethanol, methanol and ether. It is a strong oxidizer and has reductive property as well. When exposed to the air, Sodium Nitrite will be oxidized gradually, and turn into sodium nitrate on the surface. Brown nitrogen dioxide gas is released under weak acid condition. Contacting with organic matter or reducing agent will lead to explosion or combustion, furthermore, releasing toxic and irritating nitrogen oxide gas. Sodium Nitrite can also be oxidized by strong oxidizing agents, especially ammonium salt, such as ammonium nitrate, ammonium persulfate, etc., which can interact with each other to produce high heat at normal temperature, leading to combustible materials to burn. If heated to 320 ℃ or above, Sodium Nitrite will decompose to oxygen, nitrogen oxide and sodium oxide. When contacting with to organic matter, it is easy to burn and explode.
Applications:
Chromatographic analysis: Drip analysis is used to determine mercury, potassium and chlorate.
Diazotization reagents: Nitrosation reagent; Soil analysis; Determination of serum bilirubin in liver function test.
Bleaching agent for silk and linen, metal heat treatment agent; steel corrosion inhibitor; Cyanide poisoning antidote, laboratory analytical reagents. In food area, it is used as chromophores’ agents when processing meat products, as well as antimicrobial agents, preservatives. It also has applications in bleaching, electroplating and metal treatment.
Storage attentions: sodium nitrite should be stored in low temperature, dry and ventilated warehouse. Doors and Windows are tight to prevent direct sunlight. It can be stored in stock with other nitrates other than ammonium nitrate, but separated from organic matter, inflammable matter, reducing agent and fire source.