Editing Potassium nitrate (section)

{{short description|Chemical compound}}
{{redirect|Saltpeter|other uses|Saltpeter (disambiguation)}}
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 476994711
| Reference = <ref>{{GESTIS|Name=Potassium nitrate|ZVG=3630|CAS=7757-79-1|Date=2007-03-09}}</ref>
| Name = Potassium nitrate
| ImageFile = Potassium nitrate.jpg
| ImageName = Potassium nitrate
| ImageFileL1 = potassium nitrate structure.svg
| ImageFileR1 = Potassium-nitrate-superstructure-unit-cell-3D-sf.png
| IUPACName = Potassium nitrate
| OtherNames = {{Unbulleted list|Saltpeter|Saltpetre|Nitrate of potash|Nitre}}
| Section1 = {{Chembox Identifiers
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = RU45X2JN0Z
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D02051
| ChEMBL_Ref = {{ebicite|changed|EBI}}
| ChEMBL = 1644029
| InChI = 1/K.NO3/c;2-1(3)4/q+1;-1
| InChIKey = FGIUAXJPYTZDNR-UHFFFAOYAM
| SMILES = [K+].[O-][N+]([O-])=O
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/K.NO3/c;2-1(3)4/q+1;-1
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = FGIUAXJPYTZDNR-UHFFFAOYSA-N
| CASNo = 7757-79-1
| CASNo_Ref = {{cascite|correct|CAS}}
| PubChem = 24434
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 22843
| UNNumber = 1486
| RTECS = TT3700000
| EINECS = 231-818-8
}}
| Section2 = {{Chembox Properties
| Formula = KNO<sub>3</sub>
| MolarMass = 101.1032 g/mol
| Appearance = white solid
| Odor = odorless
| Solubility = {{ubl|133 g/L (0&nbsp;°C)|316 g/L (20&nbsp;°C)|383 g/L (25&nbsp;°C)|2439 g/L (100&nbsp;°C)}}<ref name=b1>{{cite book |pages=5–6 |chapter=2 |chapter-url=https://books.google.com/books?id=Q1yJNr92-YcC&pg=PA5 |title=Pyrotechnic Chemistry |author1=B. J. Kosanke |author2=B. Sturman |author3=K. Kosanke |author4=I. von Maltitz |author5=T. Shimizu |author6=M. A. Wilson |author7=N. Kubota |author8=C. Jennings-White |author9=D. Chapman |display-authors=3|publisher=Journal of Pyrotechnics |year=2004 |isbn=978-1-889526-15-7 |url-status=live |archive-url=https://web.archive.org/web/20160505033849/https://books.google.com/books?id=Q1yJNr92-YcC&pg=PA5 |archive-date=2016-05-05}}</ref>
| SolubleOther = slightly soluble in [[ethanol]]<br /> soluble in [[glycerol]], [[ammonia]]
| Density = 2.109 g/cm<sup>3</sup> (16&nbsp;°C)
| MeltingPtC = 334
| BoilingPtC = 400
| BoilingPt_notes = (decomposes)
| pKb = 15.3<ref>Kolthoff, Treatise on Analytical Chemistry, New York, Interscience Encyclopedia, Inc., 1959.</ref>
| RefractIndex = 1.335, 1.5056, 1.5604
| MagSus = −33.7·10<sup>−6</sup> cm<sup>3</sup>/mol
}}
| Section3 = {{Chembox Structure
| Coordination =
| CrystalStruct = [[Orthorhombic]], [[Aragonite]]
}}
| Section4 = {{Chembox Thermochemistry
| DeltaHf = −494.00 kJ/mol
| HeatCapacity = 95.06 J/mol K
}}
| Section7 = {{Chembox Hazards
| ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics0184.htm ICSC 0184]
| GHSPictograms = {{GHS03}} {{GHS exclamation mark}}
| HPhrases = {{H-phrases|272|315|319|335}}
| PPhrases = {{P-phrases|102|210|220|221|280}}
| MainHazards = Oxidant, harmful if swallowed, inhaled, or absorbed on skin. Causes irritation to skin and eye area.
| NFPA-H = 1
| NFPA-F = 0
| NFPA-R = 0
| NFPA-S = OX
| FlashPt = non-flammable (oxidizer)
| LD50 = 1901 mg/kg (oral, rabbit)<br />3750 mg/kg (oral, rat)<ref>{{cite journal | last1=Ema | first1=M. | last2=Kanoh | first2=S. | title=[Studies on the pharmacological bases of fetal toxicity of drugs. III. Fetal toxicity of potassium nitrate in 2 generations of rats] | journal=Nihon Yakurigaku Zasshi. Folia Pharmacologica Japonica | volume=81 | issue=6 | date=1983 | issn=0015-5691 | pmid=6618340 | pages=469–480| doi=10.1254/fpj.81.469}}</ref>
}}
| Section8 = {{Chembox Related
| OtherAnions = [[Potassium nitrite]]
| OtherCations = {{ubl|[[Lithium nitrate]]|[[Sodium nitrate]]|[[Rubidium nitrate]]|[[Caesium nitrate]]|[[Ammonium nitrate]]|[[Silver nitrate]]|[[Calcium nitrate]]}}
| OtherCompounds = {{ubl|[[Potassium sulfate]]|[[Potassium chloride]]}}
}}
}}

'''Potassium nitrate''' is a [[chemical compound]] with a sharp, salty, bitter taste and the [[chemical formula]] {{chem2|KNO3|auto=1}}. It is a [[potassium]] [[Salt (chemistry)|salt]] of [[nitric acid]]. This salt consists of potassium [[cations]] {{chem2|K+}} and [[nitrate]] [[anions]] {{chem2|NO3−}}, and is therefore an [[alkali metal nitrate]]. It occurs in nature as a mineral, [[niter]] (or ''nitre'' outside the United States).<ref name=SOED>{{cite book |title = Shorter [[Oxford English Dictionary]] |year = 2007 |edition = 6th |pages = 3804 |publisher = [[Oxford University Press]] |location = United Kingdom |isbn = 9780199206872}}</ref> 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 '''saltpetre''' (or '''saltpeter''' in the United States).<ref name=SOED/>

Major uses of potassium nitrate are in [[fertilizer]]s, [[Tree stump#Stump removal|tree stump removal]], [[rocket propellant]]s and [[firework]]s. It is one of the major constituents of traditional [[gunpowder]] (black powder).<ref name="auto1">{{Cite journal |last=Lauer |first=Klaus |date=1991 |title=The history of nitrite in human nutrition: A contribution from German cookery books |journal=Journal of Clinical Epidemiology |volume=44 |issue=3 |pages=261–264 |doi=10.1016/0895-4356(91)90037-a |issn=0895-4356 |pmid=1999685}}</ref> In [[processed meat]]s, potassium nitrate reacts with [[hemoglobin]] and [[myoglobin]] generating a red color.<ref>{{Cite journal |last=Haldane |first=J. |date=1901 |title=The Red Colour of Salted Meat |journal=The Journal of Hygiene |volume=1 |issue=1 |pages=115–122 |issn=0022-1724 |pmc=2235964 |pmid=20474105 |doi=10.1017/S0022172400000097}}</ref>