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Unit cell of sodium nitrite under standard conditions
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Names | |||
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IUPAC name
Sodium nitrite
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Identifiers | |||
3D model (JSmol)
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ChEBI | |||
ChEMBL | |||
ChemSpider | |||
ECHA InfoCard | 100.028.687 | ||
EC Number |
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E number | E250 (preservatives) | ||
KEGG | |||
PubChem CID
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RTECS number |
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UNII | |||
UN number | 1500 3287 | ||
CompTox Dashboard (EPA)
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Properties | |||
NaNO2 | |||
Molar mass | 68.9953 g/mol | ||
Appearance | white or slightly yellowish crystalline solid | ||
Density | 2.168 g/cm3 | ||
Melting point | 271 °C (520 °F; 544 K) (decomposes at 320 °C) | ||
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Solubility in methanol | 4.4 g/(100 mL) | ||
Solubility in ethanol | Soluble | ||
Solubility in diethyl ether | 0.3 g/(100 mL) | ||
Solubility in ammonia | Very soluble | ||
Acidity (pKa) | ~9 | ||
−14.5·10−6 cm3/mol | |||
Refractive index (nD)
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1.65 | ||
Structure[1] | |||
Orthorhombic | |||
Im2m | |||
a = 3.5653(8) Å, b = 5.5728(7) Å, c = 5.3846(13) Å
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Formula units (Z)
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2 | ||
Thermochemistry | |||
Std molar
entropy (S⦵298) |
106 J/(mol·K) | ||
Std enthalpy of
formation (ΔfH⦵298) |
−359 kJ/mol[2] | ||
Gibbs free energy (ΔfG⦵)
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−295 kJ/mol | ||
Pharmacology | |||
V03AB08 (WHO) | |||
Hazards | |||
GHS labelling:[3] | |||
Danger | |||
H272, H301, H319, H400 | |||
P220, P273, P301+P310, P305+P351+P338 | |||
NFPA 704 (fire diamond) | |||
489 °C (912 °F; 762 K) | |||
Lethal dose or concentration (LD, LC): | |||
LD50 (median dose)
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180 mg/kg (rats, oral) | ||
Safety data sheet (SDS) | "Sodium nitrite". Safety Data Sheet. Sigma-Aldrich. 28 December 2022. | ||
Related compounds | |||
Other anions
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Sodium nitrate | ||
Other cations
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Related compounds
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Nitrous acid | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sodium nitrite is an inorganic compound with the chemical formula NaNO2. It is a white to slightly yellowish crystalline powder that is very soluble in water and is hygroscopic. From an industrial perspective, it is the most important nitrite salt. It is a precursor to a variety of organic compounds, such as pharmaceuticals, dyes, and pesticides, but it is probably best known as a food additive used in processed meats and (in some countries) in fish products.[4]