Potassium nitrate

Potassium nitrate^[1]
Names
	IUPAC name Potassium nitrate
	Other names Saltpeter; Saltpetre; Nitrate of potash;
Identifiers
CAS Number	7757-79-1 ;
3D model (JSmol)	Interactive image;
ChEMBL	ChEMBL1644029 ;
ChemSpider	22843 ;
ECHA InfoCard	100.028.926
EC Number	231-818-8;
E number	E252 (preservatives)
KEGG	D02051 ;
PubChem CID	24434;
RTECS number	TT3700000;
UNII	RU45X2JN0Z ;
UN number	1486
CompTox Dashboard (EPA)	DTXSID4029692 ;
	InChI InChI=1S/K.NO3/c;2-1(3)4/q+1;-1 Key: FGIUAXJPYTZDNR-UHFFFAOYSA-N ; InChI=1/K.NO3/c;2-1(3)4/q+1;-1 Key: FGIUAXJPYTZDNR-UHFFFAOYAM;
	SMILES [K+].[O-][N+]([O-])=O;
Properties
Chemical formula	KNO3
Molar mass	101.1032 g/mol
Appearance	white solid
Odor	odorless
Density	2.109 g/cm3 (16 °C)
Melting point	334 °C (633 °F; 607 K)
Boiling point	400 °C (752 °F; 673 K) (decomposes)
Solubility in water	133 g/1000 g water (0 °C); 316 g/1000 g water (20 °C); 383 g/1000 g water (25 °C); 2439 g/1000 g water (100 °C)
Solubility	slightly soluble in ethanol; soluble in glycerol, ammonia
Basicity (pKb)	15.3
Magnetic susceptibility (χ)	−33.7·10−6 cm3/mol
Refractive index (nD)	1.335, 1.5056, 1.5604
Structure
Crystal structure	Orthorhombic, Aragonite
Thermochemistry
Heat capacity (C)	95.06 J/mol K
Std enthalpy of; formation (ΔfH⦵298)	-494.00 kJ/mol
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Oxidant, harmful if swallowed, inhaled, or absorbed on skin. Causes irritation to skin and eye area.
	GHS labelling:
Pictograms
Hazard statements	H272, H315, H319, H335
Precautionary statements	P102, P210, P220, P221, P280
NFPA 704 (fire diamond)	1 0 0 OX
Flash point	non-flammable (oxidizer)
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	1901 mg/kg (oral, rabbit); 3750 mg/kg (oral, rat)
Safety data sheet (SDS)	ICSC 0184
Related compounds
Other anions	Potassium nitrite
Other cations	Lithium nitrate; Sodium nitrate; Rubidium nitrate; Caesium nitrate
Related compounds	Potassium sulfate; Potassium chloride
Supplementary data page
	Potassium nitrate (data page)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Potassium nitrate is a chemical compound with a sharp, salty, bitter taste and the chemical formula K N O
₃. It is an ionic salt of potassium ions K⁺ and nitrate ions NO₃⁻, and is therefore an alkali metal nitrate. It occurs in nature as a mineral, niter (or nitre outside the US).^[5] It is a source of nitrogen, and nitrogen was named after niter. Potassium nitrate is one of several nitrogen-containing compounds collectively referred to as saltpeter (or saltpetre outside the US).^[5]

Major uses of potassium nitrate are in fertilizers, tree stump removal, rocket propellants and fireworks. It is one of the major constituents of gunpowder (black powder).^[6] In processed meats, potassium nitrate reacts with hemoglobin and myoglobin generating a red color.^[7]

^ Record of Potassium nitrate in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 2007-03-09.
^ B. J. Kosanke; B. Sturman; K. Kosanke; et al. (2004). "2". Pyrotechnic Chemistry. Journal of Pyrotechnics. pp. 5–6. ISBN 978-1-889526-15-7. Archived from the original on 2016-05-05.
^ Kolthoff, Treatise on Analytical Chemistry, New York, Interscience Encyclopedia, Inc., 1959.
^ Ema, M.; Kanoh, S. (1983). "[Studies on the pharmacological bases of fetal toxicity of drugs. III. Fetal toxicity of potassium nitrate in 2 generations of rats]". Nihon Yakurigaku Zasshi. Folia Pharmacologica Japonica. 81 (6): 469–480. doi:10.1254/fpj.81.469. ISSN 0015-5691. PMID 6618340.
^ ^a ^b Shorter Oxford English dictionary (6th ed.). United Kingdom: Oxford University Press. 2007. p. 3804. ISBN 9780199206872.
^ Lauer, Klaus (1991). "The history of nitrite in human nutrition: A contribution from German cookery books". Journal of Clinical Epidemiology. 44 (3): 261–264. doi:10.1016/0895-4356(91)90037-a. ISSN 0895-4356. PMID 1999685.
^ Haldane, J. (1901). "The Red Colour of Salted Meat". The Journal of Hygiene. 1 (1): 115–122. doi:10.1017/S0022172400000097. ISSN 0022-1724. PMC 2235964. PMID 20474105.

[1] Record of Potassium nitrate in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 2007-03-09.

[b1-2] B. J. Kosanke; B. Sturman; K. Kosanke; et al. (2004). "2". Pyrotechnic Chemistry. Journal of Pyrotechnics. pp. 5–6. ISBN 978-1-889526-15-7. Archived from the original on 2016-05-05.

[3] Kolthoff, Treatise on Analytical Chemistry, New York, Interscience Encyclopedia, Inc., 1959.

[4] Ema, M.; Kanoh, S. (1983). "[Studies on the pharmacological bases of fetal toxicity of drugs. III. Fetal toxicity of potassium nitrate in 2 generations of rats]". Nihon Yakurigaku Zasshi. Folia Pharmacologica Japonica. 81 (6): 469–480. doi:10.1254/fpj.81.469. ISSN 0015-5691. PMID 6618340.

[SOED-5] Shorter Oxford English dictionary (6th ed.). United Kingdom: Oxford University Press. 2007. p. 3804. ISBN 9780199206872.

[auto1-6] Lauer, Klaus (1991). "The history of nitrite in human nutrition: A contribution from German cookery books". Journal of Clinical Epidemiology. 44 (3): 261–264. doi:10.1016/0895-4356(91)90037-a. ISSN 0895-4356. PMID 1999685.

[7] Haldane, J. (1901). "The Red Colour of Salted Meat". The Journal of Hygiene. 1 (1): 115–122. doi:10.1017/S0022172400000097. ISSN 0022-1724. PMC 2235964. PMID 20474105.

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