Editing Potassium (section)

===Compounds===
[[Image:potassium-superoxide-unit-cell-3D-ionic.png|thumb|left|upright|Structure of solid potassium superoxide ({{chem2|KO2}}).]]

Four oxides of potassium are well studied: [[potassium oxide]] ({{chem2|K2O}}), potassium peroxide ({{chem2|K2O2}}), [[potassium superoxide]] ({{chem2|KO2}})<ref>{{cite book|last = Lide|first = David R.|date = 1998|title = Handbook of Chemistry and Physics|edition = 87th|location = Boca Raton, Florida, United States|publisher = CRC Press|isbn = 978-0-8493-0594-8|pages = 477; 520}}</ref> and [[potassium ozonide]] ({{chem2|KO3}}). The binary potassium-oxygen compounds react with water forming KOH.

KOH is a [[strong base]]. Illustrating its [[hydrophilic]] character, as much as 1.21 [[kilogram|kg]] of KOH can dissolve in a single liter of water.<ref>{{RubberBible86th|page=4–80}}</ref><ref>[[#Schultz|Schultz]], p. 94</ref> Anhydrous KOH is rarely encountered. KOH reacts readily with [[carbon dioxide]] ({{chem2|CO2}}) to produce [[potassium carbonate]] ({{chem2|K2CO3}}), and in principle could be used to remove traces of the gas from air. Like the closely related [[sodium hydroxide]], KOH reacts with [[fat]]s to produce [[soap]]s.

In general, potassium compounds are ionic and, owing to the high hydration energy of the {{chem2|K+}} ion, have excellent water solubility. The main species in water solution are the [[Metal aquo complex|aquo complexes]] {{chem2|[K(H2O)_{''n''}]+}} where ''n'' = 6 and 7.<ref name="Lincoln">Lincoln, S. F.; Richens, D. T. and Sykes, A. G. "Metal Aqua Ions" in J. A. McCleverty and T. J. Meyer (eds.) [https://www.sciencedirect.com/referencework/9780080437484/comprehensive-coordination-chemistry-ii ''Comprehensive Coordination Chemistry II''] {{Webarchive|url=https://web.archive.org/web/20190419212906/https://www.sciencedirect.com/referencework/9780080437484/comprehensive-coordination-chemistry-ii |date=2019-04-19 }}, Vol. 1, pp. 515–555, {{ISBN|978-0-08-043748-4}}.</ref>

[[Potassium heptafluorotantalate]] ({{chem2|K2[TaF7]}}) is an intermediate in the purification of [[tantalum]] from the otherwise persistent contaminant of [[niobium]].<ref name="Agulyanski">{{cite book|author=Anthony Agulyanski|editor=Anatoly Agulyanski|chapter=Fluorine chemistry in the processing of tantalum and niobium|title=Chemistry of Tantalum and Niobium Fluoride Compounds |year=2004 |publisher=Elsevier |location=Burlington |isbn=978-0-08-052902-8|edition=1st}}</ref>

[[Organopotassium compound]]s illustrate nonionic compounds of potassium. They feature highly [[Chemical polarity|polar]] [[covalent]] K–C bonds. Examples include [[benzyl potassium]] {{chem2|KCH2C6H5}}. Potassium [[Intercalation (chemistry)|intercalate]]s into [[graphite]] to give a variety of [[graphite intercalation compounds]], including {{chem2|KC8}}.