Potassium oxide (K2O) is an ionic compound of potassium and oxygen. It is a base. This pale yellow solid is the simplest oxide of potassium. It is a highly reactive compound that is rarely encountered. Some industrial materials, such as fertilizers and cements, are assayed assuming the percent composition that would be equivalent to K2O.
Potassium oxide is produced from the reaction of oxygen and potassium; this reaction affords potassium peroxide, K2O2. Treatment of the peroxide with potassium produces the oxide:[5]
Alternatively and more conveniently, K2O is synthesized by heating potassium nitrate with metallic potassium:
Other possibility is to heat potassium peroxide at 500 °C which decomposes at that temperature giving pure potassium oxide and oxygen.
Potassium hydroxide cannot be further dehydrated to the oxide but it can react with molten potassium to produce it, releasing hydrogen as a byproduct.
Properties and reactionsedit
K2O crystallises in the antifluorite structure. In this motif the positions of the anions and cations are reversed relative to their positions in CaF2, with potassium ions coordinated to 4 oxide ions and oxide ions coordinated to 8 potassium.[6][7] K2O is a basic oxide and reacts with water violently to produce the caustic potassium hydroxide. It is deliquescent and will absorb water from the atmosphere, initiating this vigorous reaction.
Term use in industryedit
The chemical formula K2O (or simply 'K') is used in several industrial contexts: the N-P-K numbers for fertilizers, in cement formulas, and in glassmaking formulas. Potassium oxide is often not used directly in these products, but the amount of potassium is reported in terms of the K2O equivalent for whatever type of potash was used, such as potassium carbonate. For example, potassium oxide is about 83% potassium by weight, while potassium chloride is only 52%. Potassium chloride provides less potassium than an equal amount of potassium oxide. Thus, if a fertilizer is 30% potassium chloride by weight, its standard potassium rating, based on potassium oxide, would be only 18.8%.
^ abcWyckoff, Ralph W.G. (1935). The Structure of Crystals (2nd ed.). Reinhold Publishing Corp. p. 25. {{cite book}}: |work= ignored (help)
^ abcDipotassium oxide in Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD) (retrieved 2014-07-04)
^Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN0-12-352651-5.
^Zintl, E.; Harder, A.; Dauth B. (1934). "Gitterstruktur der oxide, sulfide, selenide und telluride des lithiums, natriums und kaliums". Zeitschrift für Elektrochemie und Angewandte Physikalische Chemie. 40: 588–93.
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January 01, 1970
potassium, oxide, ionic, compound, potassium, oxygen, base, this, pale, yellow, solid, simplest, oxide, potassium, highly, reactive, compound, that, rarely, encountered, some, industrial, materials, such, fertilizers, cements, assayed, assuming, percent, compo. Potassium oxide K2O is an ionic compound of potassium and oxygen It is a base This pale yellow solid is the simplest oxide of potassium It is a highly reactive compound that is rarely encountered Some industrial materials such as fertilizers and cements are assayed assuming the percent composition that would be equivalent to K2O Potassium oxide Names IUPAC name potassium oxide Systematic IUPAC name potassium oxidopotassium Other names potash dipotassium oxide Identifiers CAS Number 12136 45 7 Y 3D model JSmol Interactive image ChEBI CHEBI 88321 ChemSpider 23354117 Y ECHA InfoCard 100 032 012 EC Number 235 227 6 MeSH Potassium oxide PubChem CID 25520 UNII 58D606078H Y UN number 2033 CompTox Dashboard EPA DTXSID3049754 InChI InChI 1S 2K O NKey NOTVAPJNGZMVSD UHFFFAOYSA N N SMILES O K K Properties Chemical formula K 2O Molar mass 94 196 g mol 1 Appearance Pale yellow solid Odor Odorless Density 2 32 g cm3 20 C 1 2 13 g cm3 24 C 2 Melting point 740 C 1 360 F 1 010 K 2 Solubility in water Reacts 1 forming KOH Solubility Soluble in diethyl ether 2 Structure Crystal structure Antifluorite cubic cF12 3 Space group Fm3 m No 225 3 Lattice constant a 6 436 A 3 a 90 b 90 g 90 Coordination geometry Tetrahedral K Cubic O2 Thermochemistry Heat capacity C 83 62 J mol K 4 Std molarentropy S 298 94 03 J mol K 4 Std enthalpy offormation DfH 298 363 17 kJ mol 1 4 Gibbs free energy DfG 322 1 kJ mol 1 Hazards Occupational safety and health OHS OSH Main hazards Corrosive reacts violently with water GHS labelling Pictograms Signal word Danger Hazard statements H314 Precautionary statements P260 P264 P280 P301 P330 P331 P303 P361 P353 P304 P340 P305 P351 P338 P310 P321 P363 P405 P501 NFPA 704 fire diamond 301W Safety data sheet SDS ICSC 0769 Related compounds Other anions Potassium sulfidePotassium selenidePotassium telluridePotassium polonide Other cations Lithium oxide Sodium oxide Rubidium oxide Caesium oxide Related potassium oxides Potassium peroxide Potassium superoxidePotassium ozonide Related compounds Potassium hydroxide Except where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa N verify what is Y N Infobox references Contents 1 Production 2 Properties and reactions 3 Term use in industry 4 References 5 External linksProduction editPotassium oxide is produced from the reaction of oxygen and potassium this reaction affords potassium peroxide K2O2 Treatment of the peroxide with potassium produces the oxide 5 K 2 O 2 2 K 2 K 2 O displaystyle ce K2O2 2 K gt 2 K2O nbsp Alternatively and more conveniently K2O is synthesized by heating potassium nitrate with metallic potassium 2 KNO 3 10 K 6 K 2 O N 2 displaystyle ce 2KNO3 10K gt 6K2O N2 nbsp Other possibility is to heat potassium peroxide at 500 C which decomposes at that temperature giving pure potassium oxide and oxygen 2 K 2 O 2 2 K 2 O O 2 displaystyle ce 2K2O2 gt 2K2O O2 nbsp Potassium hydroxide cannot be further dehydrated to the oxide but it can react with molten potassium to produce it releasing hydrogen as a byproduct 2 KOH 2 K 2 K 2 O H 2 displaystyle ce 2KOH 2K lt gt 2K2O H2 nbsp Properties and reactions editK2O crystallises in the antifluorite structure In this motif the positions of the anions and cations are reversed relative to their positions in CaF2 with potassium ions coordinated to 4 oxide ions and oxide ions coordinated to 8 potassium 6 7 K2O is a basic oxide and reacts with water violently to produce the caustic potassium hydroxide It is deliquescent and will absorb water from the atmosphere initiating this vigorous reaction Term use in industry editThe chemical formula K2O or simply K is used in several industrial contexts the N P K numbers for fertilizers in cement formulas and in glassmaking formulas Potassium oxide is often not used directly in these products but the amount of potassium is reported in terms of the K2O equivalent for whatever type of potash was used such as potassium carbonate For example potassium oxide is about 83 potassium by weight while potassium chloride is only 52 Potassium chloride provides less potassium than an equal amount of potassium oxide Thus if a fertilizer is 30 potassium chloride by weight its standard potassium rating based on potassium oxide would be only 18 8 References edit a b c d Anatolievich Kiper Ruslan potassium oxide chemister ru Retrieved 2014 07 04 a b c Lide David R ed 2009 CRC Handbook of Chemistry and Physics 90th ed Boca Raton Florida CRC Press ISBN 978 1 4200 9084 0 a b c Wyckoff Ralph W G 1935 The Structure of Crystals 2nd ed Reinhold Publishing Corp p 25 a href Template Cite book html title Template Cite book cite book a work ignored help a b c Dipotassium oxide in Linstrom Peter J Mallard William G eds NIST Chemistry WebBook NIST Standard Reference Database Number 69 National Institute of Standards and Technology Gaithersburg MD retrieved 2014 07 04 Holleman A F Wiberg E Inorganic Chemistry Academic Press San Diego 2001 ISBN 0 12 352651 5 Zintl E Harder A Dauth B 1934 Gitterstruktur der oxide sulfide selenide und telluride des lithiums natriums und kaliums Zeitschrift fur Elektrochemie und Angewandte Physikalische Chemie 40 588 93 Wells A F 1984 Structural Inorganic Chemistry Oxford Clarendon Press ISBN 0 19 855370 6 External links edit nbsp Wikimedia Commons has media related to Potassium oxide Retrieved from https en wikipedia org w index php title Potassium oxide amp oldid 1220860256, wikipedia, wiki, book, books, library,
