Term: Sodium nitrate
**History and Occurrence of Sodium Nitrate:**
– First shipment of saltpeter to Europe arrived in England from Peru in the early 19th century
– Mining of South American saltpeter became profitable in 1859
– Chile fought the War of the Pacific (1879–1884) for saltpeter deposits
– Crystal structure of sodium nitrate determined in 1919
– Largest accumulations found in Chile and Peru within caliche ore
– World supply mined from Atacama desert until Haber process developed
– Chile has the largest caliche reserves with active mines
– Former Chilean saltpeter mining communities declared UNESCO World Heritage sites
**Synthesis and Applications of Sodium Nitrate:**
– Industrially synthesized by neutralizing nitric acid with sodium carbonate or sodium bicarbonate
– Main uses in fertilizers and explosives
– Suitable for thermally annealing metals and storing thermal energy
– High thermal stability in molten sodium nitrate and potassium nitrate solutions
– Investigated as a phase-change material for thermal energy recovery
– Used in solar thermal power technologies, steel coating process, and diverse industrial applications
**Food Use and Health Concerns of Sodium Nitrate:**
– Used as a preservative and color fixative in cured meats and poultry
– Approved for use in the EU, Australia, and New Zealand
– Should not be confused with sodium nitrite
– Extends shelf life and prevents bacterial growth in food products
– Studies link increased nitrates to diseases like Alzheimer’s, diabetes, stomach cancer, and Parkinson’s
– Linked to higher risk of colorectal cancer and carcinogenic compound formation with protein-rich foods
**Studies and Research on Sodium Nitrate:**
– Characterization as a phase-change material and production of magnetite thin film
– Epidemiological trends on diseases like Alzheimer’s, diabetes, and cancer
– Investigations on nitrosamine intake, meat consumption, and cancer risks
– Potential cardiovascular benefits and association with colorectal cancer risk
– Dietary nitrite and nitrate benefits and health effects
**Regulatory Information and Further Reading on Sodium Nitrate:**
– EU approved additives and their E Numbers
– US FDA listing of food additives status
– Australia New Zealand food standards code on labeling ingredients
– Guidelines and regulations for sodium nitrate use
– Detailed studies, thermodynamic properties, crystallization research, and various journal articles on sodium nitrate
Sodium nitrate is the chemical compound with the formula NaNO
3. This alkali metal nitrate salt is also known as Chile saltpeter (large deposits of which were historically mined in Chile) to distinguish it from ordinary saltpeter, potassium nitrate. The mineral form is also known as nitratine, nitratite or soda niter.
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| Names | |||
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| IUPAC name
Sodium nitrate
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| Other names
Peru saltpeter
Soda niter cubic niter | |||
| Identifiers | |||
3D model (JSmol)
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| ChEMBL | |||
| ChemSpider | |||
| ECHA InfoCard | 100.028.686 | ||
| EC Number |
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| E number | E251 (preservatives) | ||
PubChem CID
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| RTECS number |
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| UNII | |||
| UN number | 1498 | ||
CompTox Dashboard (EPA)
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| Properties | |||
| NaNO3 | |||
| Molar mass | 84.9947 g/mol | ||
| Appearance | White powder or colorless crystals | ||
| Odor | sweet | ||
| Density | 2.257 g/cm3, solid | ||
| Melting point | 308 °C (586 °F; 581 K) | ||
| Boiling point | 380 °C (716 °F; 653 K) decomposes | ||
| 73 g/100 g water (0 °C) 91.2 g/100 g water (25 °C) 180 g/100 g water (100 °C) | |||
| Solubility | very soluble in ammonia, hydrazine soluble in alcohol slightly soluble in pyridine insoluble in acetone | ||
| −25.6·10−6 cm3/mol | |||
Refractive index (nD)
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1.587 (trigonal) 1.336 (rhombohedral) | ||
| Viscosity | 2.85 cP (317 °C) | ||
| Structure | |||
| trigonal and rhombohedral | |||
| Thermochemistry | |||
Heat capacity (C)
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93.05 J/(mol K) | ||
Std molar
entropy (S⦵298) |
116 J/(mol K) | ||
Std enthalpy of
formation (ΔfH⦵298) |
−467 kJ/mol | ||
Gibbs free energy (ΔfG⦵)
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−365.9 kJ/mol | ||
| Hazards | |||
| Occupational safety and health (OHS/OSH): | |||
Main hazards
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Harmful (Xn) Oxidant (O) | ||
| GHS labelling: | |||
 
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| NFPA 704 (fire diamond) | |||
| Flash point | Non-flammable | ||
| Lethal dose or concentration (LD, LC): | |||
LD50 (median dose)
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3236 mg/kg | ||
| Safety data sheet (SDS) | ICSC 0185 | ||
| Related compounds | |||
Other anions
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Sodium nitrite | ||
Other cations
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Lithium nitrate Potassium nitrate Rubidium nitrate Caesium nitrate | ||
Related compounds
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Sodium sulfate Sodium chloride | ||
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 nitrate is a white deliquescent solid very soluble in water. It is a readily available source of the nitrate anion (NO3−), which is useful in several reactions carried out on industrial scales for the production of fertilizers, pyrotechnics, smoke bombs and other explosives, glass and pottery enamels, food preservatives (esp. meats), and solid rocket propellant. It has been mined extensively for these purposes.