Editing Potassium (section)

==Commercial uses==
===Fertilizer===
[[File:Patentkali (Potassium sulfate with magnesium).jpg|thumb|Potassium sulfate/magnesium sulfate fertilizer]]
Potassium ions are an essential component of [[plant]] nutrition and are found in most [[soil]] types.<ref name="g73" /> They are used as a [[fertilizer]] in [[agriculture]], [[horticulture]], and [[hydroponic]] culture in the form of [[potassium chloride|chloride]] (KCl), [[potassium sulfate|sulfate]] ({{chem2|K2SO4}}), or [[potassium nitrate|nitrate]] ({{chem2|KNO3}}), representing the 'K' [[labeling of fertilizer|in 'NPK']]. Agricultural fertilizers consume 95% of global potassium chemical production, and about 90% of this potassium is supplied as KCl.<ref name="g73" /> The potassium content of most plants ranges from 0.5% to 2% of the harvested weight of crops, conventionally expressed as amount of {{chem2|K2O}}. Modern high-[[Crop yield|yield]] agriculture depends upon fertilizers to replace the potassium lost at harvest. Most agricultural fertilizers contain potassium chloride, while potassium sulfate is used for chloride-sensitive crops or crops needing higher sulfur content. The sulfate is produced mostly by decomposition of the complex minerals [[kainite]] ({{chem2|MgSO4*KCl*3H2O}}) and [[langbeinite]] ({{chem2|MgSO4*K2SO4}}). Only a very few fertilizers contain potassium nitrate.<ref name="Kent">{{cite book|pages = 1135–57|first = Amit H. |last = Roy| url = https://books.google.com/books?id=AYjFoLCNHYUC&pg=PA1135|isbn = 978-0-387-27843-8|publisher=Springer|title = Kent and Riegel's handbook of industrial chemistry and biotechnology|date = 2007|bibcode = 2007karh.book...... }}</ref> In 2005, about 93% of world potassium production was consumed by the fertilizer industry.<ref name="USGSYB2006" /> Furthermore, potassium can play a key role in nutrient cycling by controlling litter composition.<ref>{{cite journal |last1=Ochoa-Hueso |first1=R |last2=Delgado-Baquerizo |first2=M |last3=King |first3=PTA |last4=Benham |first4=M |last5=Arca |first5=V |last6=Power |first6=SA |title=Ecosystem type and resource quality are more important than global change drivers in regulating early stages of litter decomposition |journal=Soil Biology and Biochemistry |date=2019 |volume=129 |pages=144–152 |doi=10.1016/j.soilbio.2018.11.009 |bibcode=2019SBiBi.129..144O |s2cid=92606851 |hdl=10261/336676 |hdl-access=free }}</ref>

===Medical use===

====Potassium citrate====
[[Potassium citrate]] is used to treat a [[kidney stone]] condition called [[renal tubular acidosis]].<ref>{{cite web |title=Potassium Uses, Side Effects & Interactions |url=https://www.drugs.com/potassium.html |website=Drugs.com |language=en |access-date=2022-04-30 |archive-date=2022-04-30 |archive-url=https://web.archive.org/web/20220430065805/https://www.drugs.com/potassium.html |url-status=live }}</ref>

====Potassium chloride====
{{see also|Potassium chloride (medical use)}}

Potassium, in the form of potassium chloride is used as a medication to treat and prevent [[low blood potassium]].<ref name="WHO2008">{{cite book | title = WHO Model Formulary 2008 | year = 2009 | isbn = 978-92-4-154765-9 | vauthors = ((World Health Organization)) | veditors = Stuart MC, Kouimtzi M, Hill SR | hdl = 10665/44053 | author-link = World Health Organization | publisher = World Health Organization |page=491 }}</ref> Low blood potassium may occur due to [[vomiting]], [[diarrhea]], or certain medications.<ref name="MTM2017">{{cite web|title=Potassium chloride medical facts from Drugs.com|url=https://www.drugs.com/mtm/potassium-chloride.html|website=www.drugs.com|access-date=14 January 2017|url-status=live|archive-url=https://web.archive.org/web/20170118040410/https://www.drugs.com/mtm/potassium-chloride.html|archive-date=18 January 2017}}</ref> It is given by [[intravenous infusion|slow injection into a vein]] or by mouth.<ref name="BNF69">{{cite book|title=British national formulary : BNF 69|date=2015|publisher=British Medical Association|isbn=978-0-85711-156-2|pages=680, 684|edition=69}}</ref>

===Food additives===
Potassium sodium tartrate ({{chem2|KNaC4H4O6}}, [[Rochelle salt]]) is a main constituent of some varieties of [[baking powder]]; it is also used in the [[silvering]] of mirrors. [[Potassium bromate]] ({{chem2|KBrO3}}) is a strong oxidizer (E924), used to improve [[dough]] strength and rise height. [[Potassium bisulfite]] ({{chem2|KHSO3}}) is used as a food preservative, for example in [[wine]] and [[beer]]-making (but not in meats). It is also used to [[bleach]] textiles and straw, and in the tanning of [[leather]]s.<ref>{{cite book|chapter-url = https://books.google.com/books?id=XqKF7PqV02cC&pg=PA86|page = 86|chapter = Bleaching and Maturing Agents|title = How Baking Works: Exploring the Fundamentals of Baking Science|isbn = 978-0-470-39267-6|author = Figoni, Paula I|date= 2010|publisher=John Wiley and Sons}}</ref><ref>{{cite book|chapter-url = https://books.google.com/books?id=eblAtwEXffcC&pg=PA4|publisher=Academic Press|pages = 4–6| chapter = Uses and Exposure to Sulfites in Food|title = Advances in food research|isbn = 978-0-12-016430-1|author = Chichester, C. O.|date = July 1986}}</ref>

===Industrial===
Major potassium chemicals are potassium hydroxide, potassium carbonate, potassium sulfate, and potassium chloride. Megatons of these compounds are produced annually.<ref>[[#Schultz|Schultz]]</ref>

KOH is a strong base, which is used in industry to neutralize strong and weak [[acid]]s, to control [[pH]] and to manufacture potassium [[salt (chemistry)|salts]]. It is also used to [[saponification|saponify]] fats and [[oils]], in industrial cleaners, and in hydrolysis reactions, for example of [[esters]].<ref>{{cite book|publisher = Greenwood Publishing Group|chapter-url = https://books.google.com/books?id=UnjD4aBm9ZcC&pg=PA4|chapter = Personal Cleansing Products: Bar Soap|title = Chemical composition of everyday products|isbn = 978-0-313-32579-3|author = Toedt, John|author2 = Koza, Darrell|author3 = Cleef-Toedt, Kathleen Van|date = 2005|url-access = registration|url = https://archive.org/details/chemicalcomposit0000toed}}</ref><ref>[[#Schultz|Schultz]], p. 95</ref>

[[Potassium nitrate]] ({{chem2|KNO3}}) or saltpeter is obtained from natural sources such as [[guano]] and [[evaporites]] or manufactured via the [[Haber process]]; it is the [[oxidant]] in gunpowder ([[black powder]]) and an important agricultural fertilizer. [[Potassium cyanide]] (KCN) is used industrially to dissolve [[copper]] and precious metals, in particular [[silver]] and [[gold]], by forming [[complex (chemistry)|complexes]]. Its applications include [[gold mining]], [[electroplating]], and [[electroforming]] of these [[metal]]s; it is also used in [[organic synthesis]] to make [[nitriles]]. Potassium carbonate ({{chem2|K2CO3}} or potash) is used in the manufacture of glass, soap, color TV tubes, fluorescent lamps, textile dyes and pigments.<ref>[[#Schultz|Schultz]], p. 99</ref> [[Potassium permanganate]] ({{chem2|KMnO4}}) is an oxidizing, bleaching and purification substance and is used for production of [[saccharin]]. [[Potassium chlorate]] ({{chem2|KClO3}}) is added to matches and explosives. [[Potassium bromide]] (KBr) was formerly used as a sedative and in photography.<ref name="g73" /><!-- Potassium fluorosilicate ({{chem2|K2[SiF6]}}) is used in specialized glasses, [[ceramic]]s, and [[Vitreous enamel|enamels]]. -->

While [[potassium chromate]] ({{chem2|K2CrO4}}) is used in the manufacture of a host of different commercial products such as [[ink]]s, [[dye]]s, wood [[stain]]s (by reacting with the [[tannic acid]] in wood), [[explosive]]s, [[fireworks]], [[fly paper]], and [[safety match]]es,<ref>{{cite journal|doi = 10.1021/ed017p515|title = Ignition of the safety match|year = 1940|last1 = Siegel|first1 = Richard S.|journal = Journal of Chemical Education|volume = 17|issue = 11|pages = 515|bibcode = 1940JChEd..17..515S}}</ref><!-- looks like it is only a minor compound as a catalyst--> as well as in the tanning of leather, all of these uses are due to the chemistry of the [[chromate ion]] rather than to that of the potassium ion.<ref>{{Ullmann|contribution=Chromium Compounds|doi=10.1002/14356007.a07_067|volume=9|page=178|first1=Gerd|last1=Anger|first2=Jost|last2=Halstenberg|first3=Klaus|last3=Hochgeschwender|first4=Christoph|last4=Scherhag|first5=Ulrich|last5=Korallus|first6=Herbert|last6=Knopf|first7=Peter|last7=Schmidt|first8=Manfred|last8=Ohlinger}}</ref>

====Niche uses====
There are thousands of uses of various potassium compounds. One example is [[potassium superoxide]], {{chem2|KO2}}, an orange solid that acts as a portable source of oxygen and a carbon dioxide absorber. It is widely used in [[Rebreather#Rebreathers using an absorbent that releases oxygen|respiration systems]] in mines, submarines and spacecraft as it takes less volume than the gaseous oxygen.<ref>[[#Greenwood|Greenwood]], p. 74</ref><ref>{{cite book|url = https://archive.org/details/historyofunderwa00marx|url-access = registration|title = The history of underwater exploration|first = Robert F. |last = Marx|publisher =Courier Dover Publications| date = 1990|isbn = 978-0-486-26487-5|page=[https://archive.org/details/historyofunderwa00marx/page/93 93]}}</ref>
:{{chem2|4 KO2 + 2 CO2 → 2 K2CO3 + 3 O2}}

Another example is [[potassium cobaltinitrite]], {{chem2|K3[Co(NO2)6]}}, which is used as artist's pigment under the name of [[Aureolin]] or Cobalt Yellow.<ref name="Getts">{{cite book|publisher = Courier Dover Publications|url = https://books.google.com/books?id=bdQVgKWl3f4C&pg=PA109|title = Painting materials: A short encyclopaedia|isbn = 978-0-486-21597-6|author = Gettens, Rutherford John|author2 = Stout, George Leslie|date = 1966|pages = 109–110|access-date = 2016-01-08|archive-date = 2023-01-19|archive-url = https://web.archive.org/web/20230119031503/https://books.google.com/books?id=bdQVgKWl3f4C&pg=PA109|url-status = live}}</ref>

The stable isotopes of potassium can be [[Laser cooling|laser cooled]] and used to probe fundamental and [[Quantum technology|technological]] problems in [[Quantum mechanics|quantum physics]]. The two [[boson]]ic isotopes possess convenient [[Feshbach resonance]]s to enable studies requiring tunable interactions, while {{chem|40|K}} is one of only two stable [[fermion]]s amongst the alkali metals.<ref>{{cite journal|last1=Modugno|first1=G.|last2=Benkő|first2=C.|last3=Hannaford|first3=P.|last4=Roati|first4=G.|last5=Inguscio|first5=M.|date=1999-11-01|title=Sub-Doppler laser cooling of fermionic ${}^{40}\mathrm{K}$ atoms|journal=Physical Review A|volume=60|issue=5|pages=R3373–R3376|doi=10.1103/PhysRevA.60.R3373|arxiv=cond-mat/9908102|bibcode=1999PhRvA..60.3373M|s2cid=119001675}}</ref>

====Laboratory uses====
An [[alloy]] of sodium and potassium, [[NaK]] is a liquid used as a heat-transfer medium and a [[desiccant]] for producing [[air-free technique|dry and air-free solvents]]. It can also be used in [[reactive distillation]].<ref>{{cite book |doi=10.1021/ba-1957-0019.ch018|volume=19 |isbn=978-0-8412-0020-3 |chapter=Ch. 18: The Manufacture of Potassium and NaK |pages=169–173 |last2=Werner |first2=R. C. |last1=Jackson |first1=C. B. |year=1957 |title=Handling and uses of the alkali metals |series=Advances in Chemistry}}</ref> The ternary alloy of 12% Na, 47% K and 41% Cs has the lowest melting point of −78{{nbsp}}°C of any metallic compound.<ref name="g76" />

Metallic potassium is used in several types of [[magnetometer]]s.<ref>{{cite book|publisher=Wiley-Blackwell|chapter-url =https://books.google.com/books?id=R_Y925b97ncC&pg=PA164|chapter = Optical Pumped Magnetometer|pages = 164|title =An introduction to geophysical exploration|isbn =978-0-632-04929-5|author =Kearey, Philip|author2 =Brooks, M|author3 =Hill, Ian|date =2002}}</ref>