Potassium acetate
{{Short description|Colourless soluble salt of acetic acid}}
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 404348953
| Name = Potassium acetate
| ImageFile = Potassium_acetate skeletal.png
| ImageFileL1 = Acetate-anion-3D-balls.png
| ImageFileR1 = Potassium-3D.png
| ImageSize = 120px
| ImageName = Skeletal formula of potassium acetate
| PIN = Potassium acetate
| OtherNames = Potassium ethanoate, E261
| Section1 = {{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 127-08-2
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = M911911U02
| ChEMBL_Ref = {{ebicite|changed|EBI}}
| ChEMBL = 1201058
| PubChem = 31371
| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
| ChemSpiderID = 29104
| SMILES = CC(=O)[O-].[K+]
| InChI = 1/C2H4O2.K/c1-2(3)4;/h1H3,(H,3,4);/q;+1/p-1
| InChIKey = SCVFZCLFOSHCOH-REWHXWOFAA
| StdInChI_Ref = {{stdinchicite|changed|chemspider}}
| StdInChI = 1S/C2H4O2.K/c1-2(3)4;/h1H3,(H,3,4);/q;+1/p-1
| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
| StdInChIKey = SCVFZCLFOSHCOH-UHFFFAOYSA-M
}}
| Section2 = {{Chembox Properties
| C=2 | H=3 | O=2 | K=1
| Appearance = White deliquescent crystalline powder
| Density = 1.8{{nbsp}}g/cm3 (20{{nbsp}}°C)
1.57{{nbsp}}g/cm3 (25{{nbsp}}°C)
| Solubility = 216.7{{nbsp}}g/100{{nbsp}}mL (0.1{{nbsp}}°C)
233.8{{nbsp}}g/100{{nbsp}}mL (10{{nbsp}}°C)
268.6{{nbsp}}g/100{{nbsp}}mL (25{{nbsp}}°C)
320.8{{nbsp}}g/100{{nbsp}}mL (40{{nbsp}}°C)
390.7{{nbsp}}g/100{{nbsp}}mL (96{{nbsp}}°C){{cite book|last1 = Seidell|first1 = Atherton|last2 = Linke|first2 = William F.|year = 1952|title = Solubilities of Inorganic and Organic Compounds|publisher = Van Nostrand}}
| SolubleOther = Soluble in alcohol, liquid ammonia
Insoluble in ether, acetone
| Solubility1 = 24.24{{nbsp}}g/100{{nbsp}}g (15{{nbsp}}°C)
53.54{{nbsp}}g/100{{nbsp}}g (73.4{{nbsp}}°C)
| Solvent1 = methanol
| Solubility2 = 16.3{{nbsp}}g/100{{nbsp}}g
| Solvent2 = ethanol
| Solubility3 = 0.06{{nbsp}}g/kg (0{{nbsp}}°C)
| Solvent3 = sulfur dioxide
| MeltingPtC = 292
| BoilingPt = Decomposes
| pKa = 4.76
}}
| Section3 = {{Chembox Structure
| CrystalStruct = Monoclinic
}}
| Section4 =
| Section5 = {{Chembox Thermochemistry
| DeltaHf = −722.6{{nbsp}}kJ/mol{{Cite web|url=http://chemister.ru/Database/properties-en.php?dbid=1&id=504|title=Potassium acetate}}
| HeatCapacity = 109.38{{nbsp}}J/mol·K{{nist|name=Acetic acid, potassium salt|id=C127082|accessdate=2014-05-18|mask=FFFF|units=SI}}
| DeltaGf =
| Entropy = 150.82{{nbsp}}J/mol·K
}}
| Section6 = {{Chembox Pharmacology
| ATCCode_prefix = B05
| ATCCode_suffix = XA17
}}
| Section7 = {{Chembox Hazards
| NFPA-H = 1
| NFPA-F = 1
| NFPA-R = 0
| LD50 = 3250{{nbsp}}mg/kg (oral, rat)https://chem.nlm.nih.gov/chemidplus/rn/127-08-2 {{Dead link|date=March 2022}}
}}
}}
Potassium acetate (also called potassium ethanoate), (CH3COOK) is the potassium salt of acetic acid. It is a hygroscopic solid at room temperature.
Preparation
It can be prepared by treating a potassium-containing base such as potassium hydroxide or potassium carbonate with acetic acid:
:CH3COOH + KOH → CH3COOK + H2O
This sort of reaction is known as an acid-base neutralization reaction.
At saturation, the sesquihydrate in water solution (CH3COOK·1½H2O) begins to form semihydrate at 41.3 °C.
Applications
=Deicing=
Potassium acetate (as a substitute for calcium chloride or magnesium chloride) can be used as a deicer to remove ice or prevent its formation. It offers the advantage of being less aggressive on soils and much less corrosive:{{cite journal |last1=Gruber |first1=Michael R. |last2=Hofko |first2=Bernhard |last3=Hoffmann |first3=Markus |last4=Stinglmayr |first4=David |last5=Seifried |first5=Teresa M. |last6=Grothe |first6=Hinrich |title=Deicing performance of common deicing agents for winter maintenance with and without corrosion-inhibiting substances |journal=Cold Regions Science and Technology |date=April 2023 |volume=208 |pages=103795 |doi=10.1016/j.coldregions.2023.103795|doi-access=free }} for this reason, it is preferred for airport runways although it is more expensive.{{cite book |last1=Harrington-Hughes |first1=Kathryn |title=Handbook of test methods for evaluating chemical deicers. |date=1992 |publisher=Transportation Research Board |isbn=9789994805839}}
=Fire extinguishing=
Potassium acetate is the extinguishing agent used in Class K fire extinguishers because of its ability to cool and form a crust over burning oils.
=Food additive=
Potassium acetate is used in processed foods as a preservative and acidity regulator. In the European Union, it is labeled by the E number E261;UK Food Standards Agency: {{cite web |url=http://www.food.gov.uk/safereating/chemsafe/additivesbranch/enumberlist |title=Current EU approved additives and their E Numbers |access-date=2011-10-27}} it is also approved for usage in the USA,US Food and Drug Administration: {{cite web |url=https://www.fda.gov/Food/FoodIngredientsPackaging/FoodAdditives/ucm191033.htm#ftnT |title=Listing of Food Additives Status Part II |website=Food and Drug Administration |access-date=2011-10-27}} Australia, and New Zealand.Australia New Zealand Food Standards Code{{cite web |url=http://www.comlaw.gov.au/Details/F2011C00827 |title=Standard 1.2.4 - Labelling of ingredients |date=8 September 2011 |access-date=2011-10-27}} Potassium hydrogen diacetate (CAS #{{CAS|4251-29-0}}) with formula KH(OOCCH3)2 is a related food additive with the same E number as potassium acetate.
=Medicine and biochemistry=
In medicine, potassium acetate is used as part of electrolyte replacement protocols in the treatment of diabetic ketoacidosis because of its ability to break down to bicarbonate to help neutralize the acidotic state.
In molecular biology, potassium acetate is used to precipitate Sodium dodecyl sulfate (SDS) and SDS-bound proteins to allow their removal from DNA.
Potassium acetate is used in mixtures applied for tissue preservation, fixation, and mummification. Most museums today use a formaldehyde-based method recommended by Kaiserling in 1897 which contains potassium acetate.{{cite journal | url = https://www.uqtr.ca/plast-journal/vol8/Ulmer_7a10.pdf | author = Dale Ulmer | title = Fixation. The Key to Good Tissue Preservation | journal = Journal of the International Society for Plastination | volume = 8 | issue = 1 | pages = 7–10 | date = 1994 | doi = 10.56507/OEVY7072 | access-date = 2017-09-08 | archive-url = https://web.archive.org/web/20110516150018/http://www.uqtr.ca/plast-journal/vol8/Ulmer_7a10.pdf | archive-date = 2011-05-16 | url-status = dead }} This process was used to soak Lenin's corpse.{{Cite book | author = Andrew Nagorski | title = The Greatest Battle | publisher = Simon and Schuster | date = 2007 | page = 53}}
=Use in executions=
Potassium acetate was incorrectly used in place of potassium chloride when putting a prisoner to death in Oklahoma in January 2015.{{cite news|title=Oklahoma used wrong drug in Charles Warner's execution, autopsy report says|url=https://www.theguardian.com/us-news/2015/oct/08/oklahoma-wrong-drug-execution-charles-warner}} Charles Frederick Warner was executed on January 15, 2015 with potassium acetate; this was not public knowledge until the scheduled execution of Richard Glossip was called off.{{cite news|url= https://www.npr.org/sections/thetwo-way/2015/10/08/446862121/oklahoma-used-the-wrong-drug-to-execute-charles-warner|title=Oklahoma Used The Wrong Drug To Execute Charles Warner|author=Eyder Peralta|publisher=NPR}} In August 2017, the U.S. state of Florida executed Mark James Asay using a combination of etomidate, rocuronium bromide, and potassium acetate.{{cite news|url=http://www.sun-sentinel.com/news/florida/fl-reg-florida-execution-asay-20170824-story.html|title=Florida executes convicted killer Mark Asay using new drug|author=Jason Dearon|publisher=Sun Sentinel}} The drug was also used in the February 2023 execution of Donald Dillbeck, once again in combination with etomidate and rocuronium bromide.{{cite news|url=https://www.tallahassee.com/story/news/2023/02/23/donald-dillbeck-florida-execution-latest-updates/69904871007/|title=Convicted murderer Donald Dillbeck has been executed. Here's the latest.|author=Kathryn Varn|publisher=Tallahassee Democrat}}
=Industry=
Potassium acetate is used as a catalyst in the production of polyurethanes.Hosea Cheung, Robin S. Tanke, G. Paul Torrence "Acetic Acid" in Ullmann's Encyclopedia of Industrial Chemistry, 2005 Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a01_045}}.
Historical
It is used as a diuretic and urinary alkalizer. Before modern chemistry, it was variously called terra foliata tartari, sal Sennerti, tartarus regeneratus, arcanum tartari and sal diureticus.{{Cite book |last=Crosland |first=Maurice P. |url=https://books.google.com/books?id=kwQQaltqByAC&pg=PA104 |title=Historical Studies in the Language of Chemistry |date=2004-01-01 |publisher=Courier Corporation |isbn=978-0-486-43802-3 |language=en}} In 1760 it was used in the preparation of Cadet's fuming liquid ((CH3)2As)2O, the first organometallic compound ever produced.
References
{{reflist}}
External links
{{Commons category|Potassium acetate}}
{{Potassium compounds}}
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{{Acetates}}
{{Authority control}}