potassium bisulfate
{{Chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 448460445
| ImageFile1 = Potassium bisulfate.png
| ImageSize1 = 170px
| ImageName1 = One potassium cation and one hydrogensulfate anion
| ImageFile2 = Potassium-bisulfate-3D-balls-ionic.png
| ImageName2 = Ball-and-stick model of the component ions
| ImageFile3 = Hydrogensíran draselný.jpg
| ImageName3 = Potassium bisulfate crystals on filter paper
| IUPACName = Potassium hydrogen sulfate
| OtherNames = Potassium acid sulfate
| Section1 = {{Chembox Identifiers
|CASNo = 7646-93-7
|CASNo_Ref = {{cascite|correct|CAS}}
|UNII_Ref = {{fdacite|correct|FDA}}
|UNII = 1J1K03241F
|PubChem = 516920
|RTECS = TS7200000
|UNNumber = 2509
|EINECS = 231-594-1
|SMILES = OS(=O)(=O)[O-].[K+]
|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
|ChemSpiderID = 56396
|InChI = 1/K.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+1;/p-1
|InChIKey = CHKVPAROMQMJNQ-REWHXWOFAH
|StdInChI_Ref = {{stdinchicite|changed|chemspider}}
|StdInChI = 1S/K.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+1;/p-1
|StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
|StdInChIKey = CHKVPAROMQMJNQ-UHFFFAOYSA-M
}}
| Section2 = {{Chembox Properties
|Formula = KHSO4
|MolarMass = 136.169 g/mol
|Appearance = colorless solid
|Odor = odorless
|Density = 2.245 g/cm3
|MeltingPtC = 197
|BoilingPtC = 300
|BoilingPt_notes = (decomposes to form potassium pyrosulfate and water)
|Solubility = 36.6 g/100 mL (0 °C)
49 g/100 mL (20 °C)
121.6 g/100 mL (100 °C)
|SolubleOther = soluble in acetone, insoluble in ethanol.
|MagSus = −49.8·10−6 cm3/mol
}}
| Section3 = {{Chembox Thermochemistry
|DeltaHf = −1163.3 kJ/mol
}}
| Section4 = {{Chembox Hazards
|ExternalSDS = [http://ptcl.chem.ox.ac.uk/MSDS/PO/potassium_bisulfate.html External MSDS]
|LD50 = 2340 mg*kg−1
|GHSPictograms = {{GHS05}}{{GHS07}}
|GHSSignalWord = Danger
|HPhrases = {{H-phrases|314|335}}
|PPhrases = {{P-phrases|260|261|264|271|280|301+330+331|303+361+353|304+340|305+351+338|310|312|321|363|403+233|405|501}}
}}
| Section5 = {{Chembox Related
|OtherCompounds = Potassium sulfate
Sodium bisulfate
}}
}}
Potassium bisulfate (potassium bisulphate) is an inorganic compound with the chemical formula KHSO4 and is the potassium acid salt of sulfuric acid. It is a white, water-soluble solid.
Preparation
More than 1 million tons were produced in 1985 as the initial stage in the Mannheim process for producing potassium sulfate. The relevant conversion is the exothermic reaction of potassium chloride and sulfuric acid:{{cite book|last1=Washington Wiley|first1=Harvey|title=Principles and Practice of Agricultural Analysis: Fertilizers|date=1895|publisher=Chemical Publishing Co.|location=Easton, PA.|page=[https://archive.org/details/principlesandpr03wilegoog/page/n232 218]|url=https://archive.org/details/principlesandpr03wilegoog|quote=Potassium disulfate.|access-date=31 December 2015}}{{cite encyclopedia|author=H. Schultz |author2=G. Bauer |author3=E. Schachl |author4=F. Hagedorn |author5=P. Schmittinger |chapter=Potassium Compounds|encyclopedia=Ullmann's Encyclopedia of Industrial Chemistry|year=2005|publisher=Wiley-VCH|location=Weinheim|doi=10.1002/14356007.a22_039|isbn=978-3-527-30673-2}}
:{{chem2 | KCl + H2SO4 -> HCl + KHSO4 }}
Potassium bisulfate is a by-product in the production of nitric acid from potassium nitrate and sulfuric acid:{{cite book|last1=Pradyot|first1=Patnaik|title=Handbook of Inorganic Chemicals|date=2003|publisher=McGraw-Hill|location=New York|isbn=978-0-07-049439-8|page=636|url=https://books.google.com/books?id=Xqj-TTzkvTEC&q=0070494398}}
:{{chem2 | KNO3 + H2SO4 -> KHSO4 + HNO3 }}
Chemical properties
Thermal decomposition of potassium bisulfate forms potassium pyrosulfate:
:{{chem2 | 2 KHSO4 -> K2S2O7 + H2O }}
Above 600 °C potassium pyrosulfate converts to potassium sulfate and sulfur trioxide:{{cite book|last1=Iredelle Dillard Hinds|first1=John|title=Inorganic Chemistry: With the Elements of Physical and Theoretical Chemistry|date=1908|publisher=John Wiley & Sons.|location=New York|page=[https://archive.org/details/inorganicchemist00hinduoft/page/547 547]|url=https://archive.org/details/inorganicchemist00hinduoft|quote=Potassium disulfate.|access-date=31 December 2015}}
:{{chem2 | K2S2O7 -> K2SO4 + SO3 }}
Uses
Potassium bisulfate is commonly used to prepare potassium bitartrate for winemaking.{{cite book|isbn=978-1-4144-0453-0|title=Chemical Compounds|last1=Weisblatt|first1=Jayne|last2=Montney|first2=Charles B.|year=2006}} Potassium bisulfate is also used as a disintegrating agent in analytical chemistry or as a precursor to prepare potassium persulfate, a powerful oxidizing agent.{{cite book|last=Brauer|first=Georg|title=Handbook of Preparative Inorganic Chemistry Vol. 1, 2nd Ed.|year=1963|publisher=Academic Press|location=New York|isbn=978-0-12-126601-1|page=392|url=https://books.google.com/books?id=TLYatwAACAAJ&q=Handbook+of+Preparative+Inorganic+Chemistry}}
Occurrence
Mercallite, the mineralogical form of potassium bisulfate, occurs very rarely.{{cite web|url=https://www.mindat.org/min-2646.html|website=mindat.org|access-date=2019-05-08|title=Mercallite: Mineral information, data and localities}} Misenite is another more complex form of potassium bisulfate with the formula K8H6(SO4)7.
References
{{Reflist}}
{{Potassium compounds}}
{{Sulfates}}