Potassium compounds are compounds formed by the element potassium (K). In general, potassium compounds are ionic and, owing to the high hydration energy of the K+ ion, have excellent water solubility. The main species in water solution are the aquo complexes [K(H2O)n]+ where n = 6 and 7.[1]
Oxides and hydroxides
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Four oxides of potassium are well studied: potassium oxide (K2O), potassium peroxide (K2O2), potassium superoxide (KO2)[2] and potassium ozonide (KO3). The binary potassium-oxygen compounds react with water forming potassium hydroxide KOH.
Potassium hydroxide is a strong base. Illustrating its hydrophilic character, as much as 1.21 kg of KOH can dissolve in a single liter of water.[3][4] Anhydrous KOH is rarely encountered. KOH reacts readily with carbon dioxide CO2 to produce potassium carbonate K2CO3, and in principle could be used to remove traces of the gas from air. Like the closely related sodium hydroxide, potassium hydroxide reacts with fats to produce soaps.
Organopotassium compounds
editOrganopotassium compounds illustrate nonionic compounds of potassium. They feature highly polar covalent K–C bonds. Examples include benzyl potassium KCH2C6H5. Potassium intercalates into graphite to give a variety of graphite intercalation compounds, including KC8.
Other compounds
editPotassium heptafluorotantalate K2[TaF7] is an intermediate in the purification of tantalum from the otherwise persistent contaminant of niobium.[5]
See also
editReferences
edit- ^ Lincoln, S. F.; Richens, D. T. and Sykes, A. G. "Metal Aqua Ions" in J. A. McCleverty and T. J. Meyer (eds.) Comprehensive Coordination Chemistry II, Vol. 1, pp. 515–555, ISBN 978-0-08-043748-4.
- ^ Lide, David R. (1998). Handbook of Chemistry and Physics (87th ed.). Boca Raton, Florida, United States: CRC Press. pp. 477, 520. ISBN 978-0-8493-0594-8.
- ^ Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. p. 4–80. ISBN 0-8493-0486-5.
- ^ Schultz, p. 94
- ^ Anthony Agulyanski (2004). "Fluorine chemistry in the processing of tantalum and niobium". In Anatoly Agulyanski (ed.). Chemistry of Tantalum and Niobium Fluoride Compounds (1st ed.). Burlington: Elsevier. ISBN 9780080529028.