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{{chembox
{{chembox
| Watchedfields = changed
| Watchedfields = changed
| verifiedrevid = 477003444
| verifiedrevid = 477003444
| Name = Potassium chlorate
| Name = Potassium chlorate
| ImageFile =
| ImageFileL1 = Potassium-chlorate-composition.png
| ImageFile1 = Potassium-chlorate-composition.png
| ImageSizeL1 = 120px
| ImageSize1 = 120px
| ImageNameL1 = The structure of the ions in potassium chlorate
| ImageClass1 = skin-invert
| ImageFileR1 = Potassium-chlorate-crystal-3D-vdW.png
| ImageName1 = The structure of the ions in potassium chlorate
| ImageSizeR1 = 100px
| ImageNameR1 = The crystal structure of potassium chlorate
| ImageFile2 = Potassium chlorate-substance.jpg
| ImageSize2 = 200px
| ImageFile2 = KClO3.jpg
| ImageName2 = Potassium chlorate crystals
| ImageSize2 = 200px
| ImageName2 = Potassium chlorate crystals
| OtherNames = Potassium chlorate(V), Potcrate, Berthollet salt
| IUPACName =
| OtherNames = Potassium chlorate(V), Potcrate
| SystematicName =
|Section1={{Chembox Identifiers
| Section1 = {{Chembox Identifiers
| ChEMBL = 3188561
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 18512
| ChemSpiderID = 18512
Line 32: Line 34:
| UNNumber = 1485
| UNNumber = 1485
}}
}}
|Section2={{Chembox Properties
| Section2 = {{Chembox Properties
| Formula = KClO<sub>2</sub>
| Formula = KClO<sub>3</sub>
| MolarMass = 122.55 g mol<sup>−1</sup>
| MolarMass = 122.55 g mol<sup>−1</sup>
| Appearance = white crystals or powder
| Appearance = white crystals or powder
| Density = 2.32 g/cm<sup>3</sup>
| Density = 2.32 g/cm<sup>3</sup>
| Solubility = 3.13 g/100 mL (0 °C)<br> 4.46 g/100 mL (10 °C)<br> 8.15 g/100 mL (25 °C)<br> 13.21 g/100 mL (40 °C)<br> 53.51 g/100 mL (100 °C)<br> 183 g/100 g (190 °C)<br> 2930 g/100 g (330 °C)<ref name=sioc>{{cite book|last = Seidell|first = Atherton|last2 = Linke|first2 = William F.|year = 1952|title = Solubilities of Inorganic and Organic Compounds|publisher = Van Nostrand|url = https://books.google.com/books?id=k2e5AAAAIAAJ |accessdate = 2014-05-29}}</ref>
| Solubility = 3.13 g/100 mL (0 °C)<br> 4.46 g/100 mL (10 °C)<br> 8.15 g/100 mL (25 °C)<br> 13.21 g/100 mL (40 °C)<br> 53.51 g/100 mL (100 °C)<br> 183 g/100 g (190 °C)<br> 2930 g/100 g (330 °C)<ref name=sioc>{{cite book|last1 = Seidell|first1 = Atherton|last2 = Linke|first2 = William F.|year = 1952|title = Solubilities of Inorganic and Organic Compounds|publisher = Van Nostrand|url = https://books.google.com/books?id=k2e5AAAAIAAJ |access-date = 2014-05-29}}</ref>
| SolubleOther = soluble in [[glycerol]]<br> negligible in [[acetone]] and liquid [[ammonia]]<ref name=chemister />
| SolubleOther = soluble in [[glycerol]]<br> negligible in [[acetone]] and liquid [[ammonia]]<ref name=chemister />
| Solubility1 = 1 g/100 g (20 °C)<ref name=chemister />
| Solubility1 = 1 g/100 g (20 °C)<ref name=chemister />
Line 47: Line 49:
| MagSus = &minus;42.8·10<sup>−6</sup> cm<sup>3</sup>/mol
| MagSus = &minus;42.8·10<sup>−6</sup> cm<sup>3</sup>/mol
}}
}}
|Section3={{Chembox Structure
| Section3 = {{Chembox Structure
| Coordination =
| Coordination =
| CrystalStruct = monoclinic
| CrystalStruct = monoclinic
}}
}}
|Section4={{Chembox Thermochemistry
| Section4 = {{Chembox Thermochemistry
| DeltaHf = −391.2 kJ/mol<ref name=b1>{{cite book| author = Zumdahl, Steven S.|title =Chemical Principles 6th Ed.| publisher = Houghton Mifflin Company| year = 2009| isbn = 0-618-94690-X|page=A22}}</ref><ref name=chemister>{{cite web|url=http://chemister.ru/Database/properties-en.php?dbid=1&id=331|title=potassium chlorate|publisher=|accessdate=9 July 2015}}</ref>
| DeltaHf = −391.2 kJ/mol<ref name=b1>{{cite book| author = Zumdahl, Steven S.|title =Chemical Principles 6th Ed.| publisher = Houghton Mifflin Company| year = 2009| isbn = 978-0-618-94690-7|page=A22}}</ref><ref name=chemister>{{cite web|url=http://chemister.ru/Database/properties-en.php?dbid=1&id=331|title=potassium chlorate|access-date=9 July 2015}}</ref>
| Entropy = 142.97 J/mol·K<ref name=b1 /><ref name=chemister />
| Entropy = 142.97 J/mol·K<ref name=b1 /><ref name=chemister />
| DeltaGf = -289.9 kJ/mol<ref name=chemister />
| DeltaGf = -289.9 kJ/mol<ref name=chemister />
| HeatCapacity = 100.25 J/mol·K<ref name=chemister />
| HeatCapacity = 100.25 J/mol·K<ref name=chemister />
}}
}}
| Section5 =
|Section7={{Chembox Hazards
| Section6 =
| Section7 = {{Chembox Hazards
| ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics0548.htm ICSC 0548]
| ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics0548.htm ICSC 0548]
| GHSPictograms = {{GHS03}}{{GHS07}}{{GHS09}}<ref name="sigma">{{cite web|url=http://www.sigmaaldrich.com/catalog/product/sial/255572|title=Potassium chlorate|publisher=|accessdate=9 July 2015}}</ref>
| GHSPictograms = {{GHS03}}{{GHS07}}{{GHS09}}<ref name="sigma">{{cite web|url=https://www.sigmaaldrich.com/US/en/product/sigald/255572|title=Potassium chlorate|access-date=14 February 2022}}</ref>
| GHSSignalWord = Danger
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|271|302|332|411}}<ref name="sigma" />
| HPhrases = {{H-phrases|271|302|332|411}}<ref name="sigma" />
Line 67: Line 71:
| NFPA-R = 3
| NFPA-R = 3
| NFPA-S = OX
| NFPA-S = OX
| LD50 = 1870 mg/kg (oral, rat)<ref>{{cite web|url=http://chem.sis.nlm.nih.gov/chemidplus/rn/3811-04-9|title=ChemIDplus - 3811-04-9 - VKJKEPKFPUWCAS-UHFFFAOYSA-M - Potassium chlorate - Similar structures search, synonyms, formulas, resource links, and other chemical information.|author=Michael Chambers|publisher=|accessdate=9 July 2015}}</ref>
| LD50 = 1870 mg/kg (oral, rat)<ref>{{cite web|url=https://chem.nlm.nih.gov/chemidplus/rn/3811-04-9|title=ChemIDplus - 3811-04-9 - VKJKEPKFPUWCAS-UHFFFAOYSA-M - Potassium chlorate - Similar structures search, synonyms, formulas, resource links, and other chemical information.|author=Michael Chambers|access-date=9 July 2015}}</ref>
}}
}}
|Section8={{Chembox Related
| Section8 = {{Chembox Related
| OtherAnions = [[Potassium bromate]]<br>[[Potassium iodate]]<br>[[Potassium nitrate]]
| OtherAnions = [[Potassium bromate]]<br>[[Potassium iodate]]<br>[[Potassium nitrate]]
| OtherCations = [[Ammonium chlorate]]<br>[[Sodium chlorate]]<br>[[Barium chlorate]]
| OtherCations = [[Ammonium chlorate]]<br>[[Sodium chlorate]]<br>[[Barium chlorate]]
Line 76: Line 80:
}}
}}


'''Potassium chlorate''' is a compound containing [[potassium]], [[chlorine]] and [[oxygen]], with the molecular formula KClO<sub>3</sub>. In its pure form, it is a white crystalline substance. It is the most common [[chlorate]] in industrial use. It is used,
'''Potassium chlorate''' is the [[inorganic compound]] with the molecular formula KClO<sub>3</sub>. In its pure form, it is a white solid. After [[sodium chlorate]], it is the second most common [[chlorate]] in industrial use. It is a strong [[oxidizing agent]] and its most important application is in safety [[match]]es.<ref name="ullmann_2000">{{cite book
| last1=Vogt | first1=Helmut
* as an [[oxidizing agent]],
| last2=Balej | first2=Jan
* to prepare [[oxygen]],
| last3=Bennett | first3=John E.
* as a [[disinfectant]],
| last4=Wintzer | first4=Peter
* in safety [[match]]es,
| last5=Sheikh | first5=Saeed Akbar
* in [[explosives]] and [[fireworks]],
| last6=Gallone | first6=Patrizio
* in [[Plant cultivation|cultivation]], forcing the blossoming stage of the [[longan]] tree, causing it to produce fruit in warmer climates.<ref>{{Cite journal
| date=June 15, 2000
| last1 = Manochai | first1 = P.
| editor-last=Ullmann
| last2 = Sruamsiri | first2 = P.
| title=Ullmann's Encyclopedia of Industrial Chemistry
| last3 = Wiriya-alongkorn | first3 = W.
| publisher=Wiley‐VCH Verlag
| last4 = Naphrom | first4 = D.
| chapter=Chlorine Oxides and Chlorine Oxygen Acids
| last5 = Hegele | first5 = M.
| isbn=9783527303854
| last6 = Bangerth | first6 = F.
| doi=10.1002/14356007.a06_483
| title = Year around off season flower induction in longan (Dimocarpus longan, Lour.) trees by KClO3 applications: potentials and problems
}}</ref> In other applications it is mostly obsolete and has been replaced by safer alternatives in recent decades. It has been used
| journal = Scientia Horticulturae
* in [[fireworks]], [[propellant]]s and [[explosives]],
| volume = 104
* to prepare [[oxygen]], both in the lab and in [[chemical oxygen generator]]s,
| issue = 4
* as a [[disinfectant]], for example in [[dentifrice]]s and medical [[mouthwash]]es,
| pages = 379–390
* in [[agriculture]] as an [[herbicide]].
| location = Department of Horticulture, Maejo University, Chiang Mai, Thailand; Department of Horticulture, Chiang Mai University, Chiang Mai, Thailand; Institute of Special Crops and Crop Physiology, University of Hohenheim, 70593 Stuttgart, Germany
| date = February 12, 2005
| url = http://www.actahort.org/books/863/863_48.htm
| accessdate = November 28, 2010 | doi=10.1016/j.scienta.2005.01.004}}</ref>


==Production==
==Production==
On the industrial scale, potassium chlorate is produced by the [[salt metathesis reaction]] of [[sodium chlorate]] and [[potassium chloride]]:
On the industrial scale, potassium chlorate is produced by the Liebig process: passing chlorine into hot [[calcium hydroxide]], subsequently adding [[potassium chloride]]:<ref>Реми, Г. Курс неорганической химиию, т. 1/Перевод с немецкого под ред. А. В. Новосёловой. Москва:Мир, 1972.- с. 770//(translated from:) Heinrich Remy. Lehrbuch der anorganischen Chemie. XI Auflage. Band 1. Leipzig:Geest & Portig K.-G., 1960.</ref>
:{{chem2 | NaClO3 + KCl -> NaCl + KClO3 }}
:6 Ca(OH)<sub>2</sub> + 6 Cl<sub>2</sub> → Ca(ClO<sub>3</sub>)<sub>2</sub> + 5 CaCl<sub>2</sub> + 6 H<sub>2</sub>O
The reaction is driven by the low solubility of potassium chlorate in water. The equilibrium of the reaction is shifted to the right hand side by the continuous precipitation of the product ([[Le Chatelier's Principle]]). The precursor sodium chlorate is produced industrially in very large quantities by [[electrolysis]] of [[sodium chloride]], common table salt.<ref name="ullmann_2000"/>
:Ca(ClO<sub>3</sub>)<sub>2</sub> + 2 KCl → 2 KClO<sub>3</sub> + CaCl<sub>2</sub>
The [[electrolysis]] of [[Potassium chloride|KCl]] in aqueous solution is also used sometimes, in which elemental chlorine formed at the [[anode]] react with KOH ''[[in situ]]''. The low [[solubility]] of KClO<sub>3</sub> in water causes the salt to conveniently isolate itself from the [[reaction mixture]] by simply precipitating out of solution.


The direct electrolysis of [[Potassium chloride|KCl]] in aqueous solution is also used sometimes, in which elemental chlorine formed at the [[anode]] reacts with KOH ''[[in situ]]''. The low [[solubility]] of KClO<sub>3</sub> in water causes the salt to conveniently isolate itself from the [[reaction mixture]] by simply precipitating out of solution.
Potassium chlorate can be produced in small amounts by [[disproportionation]] in a [[sodium hypochlorite]] solution followed by [[salt metathesis reaction|metathesis reaction]] with potassium chloride:<ref>{{cite web|url=http://chemistry.about.com/od/makechemicalsyourself/a/Potassium-Chlorate-From-Bleach-And-Salt-Substitute.htm|title=Potassium Chlorate Synthesis (Substitute) Formula|author=Anne Marie Helmenstine, Ph.D.|work=About.com Education|accessdate=9 July 2015}}</ref>

:3 NaOCl<sub>(aq)</sub> → 2 NaCl<sub>(s)</sub> + NaClO<sub>3</sub><sub>(aq)</sub>
Potassium chlorate can be produced in small amounts by [[disproportionation]] in a [[sodium hypochlorite]] solution followed by [[salt metathesis reaction|metathesis reaction]] with potassium chloride:<ref>{{cite web|url=http://chemistry.about.com/od/makechemicalsyourself/a/Potassium-Chlorate-From-Bleach-And-Salt-Substitute.htm|title=Potassium Chlorate Synthesis (Substitute) Formula|author=Anne Marie Helmenstine, Ph.D.|work=About.com Education|access-date=9 July 2015}}</ref>
:KCl<sub>(aq)</sub> + NaClO<sub>3</sub><sub>(aq)</sub> → NaCl<sub>(aq)</sub> + KClO<sub>3</sub><sub>(s)</sub>
:{{chem2 | 3 NaOCl -> 2 NaCl + NaClO3 }}
:{{chem2 | KCl + NaClO3 -> NaCl + KClO3 }}


It can also be produced by passing chlorine gas into a hot solution of caustic potash:<ref name="Pradyot Patnaik 2002">Pradyot Patnaik. ''Handbook of Inorganic Chemicals''. McGraw-Hill, 2002, {{ISBN|0-07-049439-8}}</ref>
It can also be produced by passing chlorine gas into a hot solution of caustic potash:<ref name="Pradyot Patnaik 2002">Pradyot Patnaik. ''Handbook of Inorganic Chemicals''. McGraw-Hill, 2002, {{ISBN|0-07-049439-8}}</ref>
:{{chem2 | 3 Cl2 + 6 KOH -> KClO3 + 5 KCl + 3 H2O }}
:3 Cl<sub>2(g)</sub> + 6 KOH<sub>(aq)</sub> → KClO<sub>3(aq)</sub> + 5 KCl<sub>(aq)</sub> + 3 H<sub>2</sub>O<sub>(l)</sub>

According to [[X-ray crystallography]], potassium chlorate is a dense salt-like structure consisting of chlorate and potassium ions in close association.
[[Image:Potassium-chlorate-crystal-3D-vdW.png|thumb|left|100px|The crystal structure of potassium chlorate. Color code: red = O, violet = K, green = Cl]]


==Uses==
==Uses==
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Potassium chlorate was one key ingredient in early [[firearms]] [[percussion cap]]s (primers). It continues in that application, where not supplanted by [[potassium perchlorate]].
Potassium chlorate was one key ingredient in early [[firearms]] [[percussion cap]]s (primers). It continues in that application, where not supplanted by [[potassium perchlorate]].


Chlorate-based [[propellant]]s are more efficient than traditional [[gunpowder]] and are less susceptible to damage by water. However, they can be extremely unstable in the presence of [[sulfur]] or [[phosphorus]] and are much more expensive. Chlorate propellants must be used only in equipment designed for them; failure to follow this precaution is a common source of accidents. Potassium chlorate, often in combination with [[silver fulminate]], is used in trick [[Bang snaps|noise-makers]] known as "crackers", "snappers", "pop-its", or "bang-snaps", a popular type of novelty [[firecracker|firework.]]
Chlorate-based [[propellant]]s are more efficient than traditional [[gunpowder]] and are less susceptible to damage by water. However, they can be extremely unstable in the presence of [[sulfur]] or [[phosphorus]] and are much more expensive. Chlorate propellants must be used only in equipment designed for them; failure to follow this precaution is a common source of accidents. Potassium chlorate, often in combination with [[silver fulminate]], is used in trick [[Bang snaps|noise-makers]] known as "crackers", "snappers", "pop-its", "caps" or "bang-snaps", a popular type of novelty [[firecracker|firework.]]


Another application of potassium chlorate is as the oxidizer in a [[smoke composition]] such as that used in [[smoke grenade]]s. Since 2005, a cartridge with potassium chlorate mixed with [[lactose]] and [[rosin]] is used for generating the white smoke signaling the election of new pope by a [[papal conclave]].<ref>{{cite news |title=New Round of Voting Fails to Name a Pope |author=Daniel J. Wakin and Alan Cowell |url=https://www.nytimes.com/2013/03/14/world/europe/vatican-pope-selection-conclave.html |newspaper=[[The New York Times]] |date=March 13, 2013 |accessdate=March 13, 2013}}</ref>
Another application of potassium chlorate is as the oxidizer in a [[smoke composition]] such as that used in [[smoke grenade]]s. Since 2005, a cartridge with potassium chlorate mixed with [[lactose]] and [[rosin]] is used for generating the white smoke signaling the election of new pope by a [[papal conclave]].<ref>{{cite news |title=New Round of Voting Fails to Name a Pope |author=Daniel J. Wakin and Alan Cowell |url=https://www.nytimes.com/2013/03/14/world/europe/vatican-pope-selection-conclave.html |newspaper=[[The New York Times]] |date=March 13, 2013 |access-date=March 13, 2013}}</ref>


Potassium chlorate is often used in high school and college laboratories to generate oxygen gas. {{Citation needed|date=June 2009}} It is a far cheaper source than a pressurized or cryogenic oxygen tank. Potassium chlorate readily decomposes if heated while in contact with a [[catalyst]], typically [[manganese dioxide|manganese(IV) dioxide]] (MnO<sub>2</sub>). Thus, it may be simply placed in a test tube and heated over a burner. If the test tube is equipped with a one-holed stopper and hose, warm oxygen can be drawn off. The reaction is as follows:
High school and college laboratories often use potassium chlorate to generate oxygen gas. {{Citation needed|date=June 2009}} It is a far cheaper source than a pressurized or cryogenic oxygen tank. Potassium chlorate readily decomposes if heated while in contact with a [[catalyst]], typically [[manganese dioxide|manganese(IV) dioxide]] (MnO<sub>2</sub>). Thus, it may be simply placed in a test tube and heated over a burner. If the test tube is equipped with a one-holed stopper and hose, warm oxygen can be drawn off. The reaction is as follows:
:{{chem2 | 2 KClO3(s) + MnO2(cat) -> 3 O2(g) + 2 KCl(s) }}

:2 KClO<sub>3(s)</sub> → 3 O<sub>2(g)</sub> + 2 KCl<sub>(s)</sub>


Heating it in the absence of a catalyst converts it into [[potassium perchlorate]]:<ref name="Pradyot Patnaik 2002"/>
Heating it in the absence of a catalyst converts it into [[potassium perchlorate]]:<ref name="Pradyot Patnaik 2002"/>
:4 KClO<sub>3</sub> → 3 KClO<sub>4</sub> + KCl
:{{chem2 | 4 KClO3 -> 3 KClO4 + KCl }}


With further heating, potassium perchlorate decomposes to [[potassium chloride]] and oxygen:
With further heating, potassium perchlorate decomposes to [[potassium chloride]] and oxygen:
:KClO<sub>4</sub> → KCl + 2 O<sub>2</sub>
:{{chem2 | KClO4 -> KCl + 2 O2 }}


The safe performance of this reaction requires very pure reagents and careful temperature control. Molten potassium chlorate is an extremely powerful oxidizer and spontaneously reacts with many common materials such as sugar. Explosions have resulted from liquid chlorates spattering into the latex or PVC tubes of oxygen generators, as well as from contact between chlorates and hydrocarbon sealing greases. Impurities in potassium chlorate itself can also cause problems. When working with a new batch of potassium chlorate, it is advisable to take a small sample (~1&nbsp;gram) and heat it strongly on an open glass plate. Contamination may cause this small quantity to explode, indicating that the chlorate should be discarded.
The safe performance of this reaction requires very pure reagents and careful temperature control. Molten potassium chlorate is an extremely powerful oxidizer and spontaneously reacts with many common materials such as sugar. Explosions have resulted from liquid chlorates spattering into the latex or PVC tubes of oxygen generators and from contact between chlorates and hydrocarbon sealing greases. Impurities in potassium chlorate itself can also cause problems. When working with a new batch of potassium chlorate, it is advisable to take a small sample (~1&nbsp;gram) and heat it strongly on an open glass plate. Contamination may cause this small quantity to explode, indicating that the chlorate should be discarded.


Potassium chlorate is used in [[chemical oxygen generator]]s (also called chlorate candles or oxygen candles), employed as oxygen-supply systems of e.g. aircraft, space stations, and submarines, and has been responsible for at least one [[ValuJet Flight 592|plane crash]]. A fire on the space station [[Mir]] was also traced to this substance. The decomposition of potassium chlorate was also used to provide the oxygen supply for [[limelight]]s.
Potassium chlorate is used in [[chemical oxygen generator]]s (also called chlorate candles or oxygen candles), employed as oxygen-supply systems of e.g. aircraft, space stations, and submarines, and has been responsible for at least one [[ValuJet Flight 592|plane crash]]. A fire on the space station [[Mir]] was traced to oxygen generation candles that use a similar lithium perchlorate. The decomposition of potassium chlorate was also used to provide the oxygen supply for [[limelight]]s.


Potassium chlorate is used also as a [[pesticide]]. In Finland it was sold under trade name Fegabit.
Potassium chlorate is used also as a [[pesticide]]. In Finland it was sold under trade name Fegabit.


Potassium chlorate can react with sulfuric acid to form a highly reactive solution of chloric acid and potassium sulfate:
Potassium chlorate can react with sulfuric acid to form a highly reactive solution of chloric acid and potassium sulfate:
:{{chem2 | 2 KClO3 + H2SO4 -> 2 HClO3 + K2SO4 }}

:2 KClO<sub>3</sub> + H<sub>2</sub>SO<sub>4</sub> → 2 HClO<sub>3</sub> + K<sub>2</sub>SO<sub>4</sub>


The solution so produced is sufficiently reactive that it spontaneously ignites if combustible material (sugar, paper, etc.) is present.
The solution so produced is sufficiently reactive that it spontaneously ignites if combustible material (sugar, paper, etc.) is present.


In schools, molten potassium chlorate is used in the dramatic [[screaming jelly babies]], [[Gummy bear]], [[Haribo]], and [[Trolli]] candy demonstration where the candy is dropped into the molten salt.
[[File:Screaming gummy bear (chlorate) abridged.ogg|thumb|Candy being dropped into molten salt]]
In schools, molten potassium chlorate is used in [[screaming jelly babies]], [[Gummy bear]], [[Haribo]], and [[Trolli]] candy demonstration where the candy is dropped into the molten salt.


In chemical labs it is used to oxidize HCl and release small amounts of gaseous chlorine.
In chemical labs it is used to oxidize HCl and release small amounts of gaseous chlorine.


Insurgents in [[Afghanistan]] also use potassium chlorate extensively as a key component in the production of [[improvised explosive devices]]. When significant effort was made to reduce the availability of [[ammonium nitrate]] fertilizer in Afghanistan, IED makers started using potassium chlorate as a cheap and effective alternative. In 2013, 60% of IEDs in Afghanistan used potassium chlorate, making it the most common ingredient used in IEDs.<ref>{{cite news|url=https://www.usatoday.com/story/news/world/2013/06/25/ammonium-nitrate-potassium-chlorate-ieds-afghanistan/2442191/ |title=Afghan bomb makers shifting to new explosives for IEDs |publisher=USAToday.com |date= June 25, 2013|accessdate=2013-06-25}}</ref>
Militant groups in [[Afghanistan]] also use potassium chlorate extensively as a key component in the production of [[improvised explosive devices]] (IEDs). When significant effort was made to reduce the availability of [[ammonium nitrate]] fertilizer in Afghanistan, IED makers started using potassium chlorate as a cheap and effective alternative. In 2013, 60% of IEDs in Afghanistan used potassium chlorate, making it the most common ingredient used in IEDs.<ref>{{cite news|url=https://www.usatoday.com/story/news/world/2013/06/25/ammonium-nitrate-potassium-chlorate-ieds-afghanistan/2442191/ |title=Afghan bomb makers shifting to new explosives for IEDs |publisher=USAToday.com |date= June 25, 2013|access-date=2013-06-25}}</ref>
Potassium chlorate was also the main ingredient in the car bomb used in [[2002 Bali bombings]] that killed 202 people.
Potassium chlorate was also the main ingredient in the car bomb used in [[2002 Bali bombings]] that killed 202 people.

Potassium chlorate is used to force the blossoming stage of the [[longan]] tree, causing it to produce fruit in warmer climates.<ref>{{Cite journal
| last1 = Manochai | first1 = P.
| last2 = Sruamsiri | first2 = P.
| last3 = Wiriya-alongkorn | first3 = W.
| last4 = Naphrom | first4 = D.
| last5 = Hegele | first5 = M.
| last6 = Bangerth | first6 = F.
| title = Year around off-season flower induction in longan (Dimocarpus longan, Lour.) trees by KClO3 applications: potentials and problems
| journal = Scientia Horticulturae
| volume = 104
| issue = 4
| pages = 379–390
| location = Department of Horticulture, Maejo University, Chiang Mai, Thailand; Department of Horticulture, Chiang Mai University, Chiang Mai, Thailand; Institute of Special Crops and Crop Physiology, University of Hohenheim, 70593 Stuttgart, Germany
| date = February 12, 2005
| url = http://www.actahort.org/books/863/863_48.htm
| access-date = November 28, 2010 | doi=10.1016/j.scienta.2005.01.004}}</ref>


==Safety==
==Safety==
Potassium chlorate should be handled with care. It reacts vigorously, and in some cases spontaneously ignites or explodes, when mixed with many [[combustible]] materials. It burns vigorously in combination with virtually any combustible material, even those normally only slightly flammable (including ordinary dust and lint). Mixtures of potassium chlorate and a fuel can ignite by contact with sulfuric acid, so it should be kept away from this reagent.
Potassium chlorate should be handled with care. It reacts vigorously, and in some cases spontaneously ignites or explodes, when mixed with many [[combustible]] materials. It burns vigorously in combination with virtually any combustible material, even those normally only slightly flammable (including ordinary dust and lint). Mixtures of potassium chlorate and a fuel can ignite by contact with sulfuric acid, so it should be kept away from this reagent.
[[Sulfur]] should be avoided in pyrotechnic compositions containing potassium chlorate, as these mixtures are prone to spontaneous [[deflagration]]. Most sulfur contains trace quantities of sulfur-containing acids, and these can cause spontaneous ignition - "Flowers of sulfur" or "sublimed sulfur", despite the overall high purity, contains significant amounts of sulfur acids. Also, mixtures of potassium chlorate with any compound with ignition promoting properties (ex. [[antimony(III) sulfide]]) are very dangerous to prepare, as they are extremely shock sensitive.
[[Sulfur]] should be avoided in pyrotechnic compositions containing potassium chlorate, as these mixtures are prone to spontaneous [[deflagration]]. Most sulfur contains trace quantities of sulfur-containing acids, and these can cause spontaneous ignition - "Flowers of sulfur" or "sublimed sulfur", despite the overall high purity, contains significant amounts of sulfur acids. Also, mixtures of potassium chlorate with any compound with ignition promoting properties, such as [[antimony(III) sulfide]], are very dangerous to prepare, as they are extremely shock sensitive.


==See also==
==See also==
Line 165: Line 186:


{{Potassium compounds}}
{{Potassium compounds}}
{{Chlorates}}


[[Category:Potassium compounds]]
[[Category:Potassium compounds]]

Latest revision as of 01:11, 17 December 2024

Potassium chlorate
The structure of the ions in potassium chlorate
Potassium chlorate crystals
Names
Other names
Potassium chlorate(V), Potcrate, Berthollet salt
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.021.173 Edit this at Wikidata
EC Number
  • 223-289-7
RTECS number
  • FO0350000
UNII
UN number 1485
  • InChI=1S/ClHO3.K/c2-1(3)4;/h(H,2,3,4);/q;+1/p-1 checkY
    Key: VKJKEPKFPUWCAS-UHFFFAOYSA-M checkY
  • InChI=1/ClHO3.K/c2-1(3)4;/h(H,2,3,4);/q;+1/p-1
    Key: VKJKEPKFPUWCAS-REWHXWOFAC
  • [K+].[O-]Cl(=O)=O
Properties
KClO3
Molar mass 122.55 g mol−1
Appearance white crystals or powder
Density 2.32 g/cm3
Melting point 356 °C (673 °F; 629 K)
Boiling point 400 °C (752 °F; 673 K) decomposes[1]
3.13 g/100 mL (0 °C)
4.46 g/100 mL (10 °C)
8.15 g/100 mL (25 °C)
13.21 g/100 mL (40 °C)
53.51 g/100 mL (100 °C)
183 g/100 g (190 °C)
2930 g/100 g (330 °C)[2]
Solubility soluble in glycerol
negligible in acetone and liquid ammonia[1]
Solubility in glycerol 1 g/100 g (20 °C)[1]
−42.8·10−6 cm3/mol
1.40835
Structure
monoclinic
Thermochemistry
100.25 J/mol·K[1]
142.97 J/mol·K[3][1]
−391.2 kJ/mol[3][1]
-289.9 kJ/mol[1]
Hazards
GHS labelling:
GHS03: OxidizingGHS07: Exclamation markGHS09: Environmental hazard[4]
Danger
H271, H302, H332, H411[4]
P220, P273[4]
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g. hydrogen peroxideSpecial hazard OX: Oxidizer. E.g. potassium perchlorate
2
0
3
OX
Lethal dose or concentration (LD, LC):
1870 mg/kg (oral, rat)[5]
Safety data sheet (SDS) ICSC 0548
Related compounds
Other anions
 Potassium bromate
Potassium iodate
Potassium nitrate
Other cations
 Ammonium chlorate
Sodium chlorate
Barium chlorate
Related compounds
 Potassium chloride
Potassium hypochlorite
Potassium chlorite
Potassium perchlorate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Potassium chlorate is the inorganic compound with the molecular formula KClO3. In its pure form, it is a white solid. After sodium chlorate, it is the second most common chlorate in industrial use. It is a strong oxidizing agent and its most important application is in safety matches.[6] In other applications it is mostly obsolete and has been replaced by safer alternatives in recent decades. It has been used

Production

[edit]

On the industrial scale, potassium chlorate is produced by the salt metathesis reaction of sodium chlorate and potassium chloride:

NaClO3 + KCl → NaCl + KClO3

The reaction is driven by the low solubility of potassium chlorate in water. The equilibrium of the reaction is shifted to the right hand side by the continuous precipitation of the product (Le Chatelier's Principle). The precursor sodium chlorate is produced industrially in very large quantities by electrolysis of sodium chloride, common table salt.[6]

The direct electrolysis of KCl in aqueous solution is also used sometimes, in which elemental chlorine formed at the anode reacts with KOH in situ. The low solubility of KClO3 in water causes the salt to conveniently isolate itself from the reaction mixture by simply precipitating out of solution.

Potassium chlorate can be produced in small amounts by disproportionation in a sodium hypochlorite solution followed by metathesis reaction with potassium chloride:[7]

3 NaOCl → 2 NaCl + NaClO3
KCl + NaClO3 → NaCl + KClO3

It can also be produced by passing chlorine gas into a hot solution of caustic potash:[8]

3 Cl2 + 6 KOH → KClO3 + 5 KCl + 3 H2O

According to X-ray crystallography, potassium chlorate is a dense salt-like structure consisting of chlorate and potassium ions in close association.

The crystal structure of potassium chlorate. Color code: red = O, violet = K, green = Cl

Uses

[edit]
Potassium chlorate burning sugar

Potassium chlorate was one key ingredient in early firearms percussion caps (primers). It continues in that application, where not supplanted by potassium perchlorate.

Chlorate-based propellants are more efficient than traditional gunpowder and are less susceptible to damage by water. However, they can be extremely unstable in the presence of sulfur or phosphorus and are much more expensive. Chlorate propellants must be used only in equipment designed for them; failure to follow this precaution is a common source of accidents. Potassium chlorate, often in combination with silver fulminate, is used in trick noise-makers known as "crackers", "snappers", "pop-its", "caps" or "bang-snaps", a popular type of novelty firework.

Another application of potassium chlorate is as the oxidizer in a smoke composition such as that used in smoke grenades. Since 2005, a cartridge with potassium chlorate mixed with lactose and rosin is used for generating the white smoke signaling the election of new pope by a papal conclave.[9]

High school and college laboratories often use potassium chlorate to generate oxygen gas. [citation needed] It is a far cheaper source than a pressurized or cryogenic oxygen tank. Potassium chlorate readily decomposes if heated while in contact with a catalyst, typically manganese(IV) dioxide (MnO2). Thus, it may be simply placed in a test tube and heated over a burner. If the test tube is equipped with a one-holed stopper and hose, warm oxygen can be drawn off. The reaction is as follows:

2 KClO3(s) + MnO2(cat) → 3 O2(g) + 2 KCl(s)

Heating it in the absence of a catalyst converts it into potassium perchlorate:[8]

4 KClO3 → 3 KClO4 + KCl

With further heating, potassium perchlorate decomposes to potassium chloride and oxygen:

KClO4 → KCl + 2 O2

The safe performance of this reaction requires very pure reagents and careful temperature control. Molten potassium chlorate is an extremely powerful oxidizer and spontaneously reacts with many common materials such as sugar. Explosions have resulted from liquid chlorates spattering into the latex or PVC tubes of oxygen generators and from contact between chlorates and hydrocarbon sealing greases. Impurities in potassium chlorate itself can also cause problems. When working with a new batch of potassium chlorate, it is advisable to take a small sample (~1 gram) and heat it strongly on an open glass plate. Contamination may cause this small quantity to explode, indicating that the chlorate should be discarded.

Potassium chlorate is used in chemical oxygen generators (also called chlorate candles or oxygen candles), employed as oxygen-supply systems of e.g. aircraft, space stations, and submarines, and has been responsible for at least one plane crash. A fire on the space station Mir was traced to oxygen generation candles that use a similar lithium perchlorate. The decomposition of potassium chlorate was also used to provide the oxygen supply for limelights.

Potassium chlorate is used also as a pesticide. In Finland it was sold under trade name Fegabit.

Potassium chlorate can react with sulfuric acid to form a highly reactive solution of chloric acid and potassium sulfate:

2 KClO3 + H2SO4 → 2 HClO3 + K2SO4

The solution so produced is sufficiently reactive that it spontaneously ignites if combustible material (sugar, paper, etc.) is present.

Candy being dropped into molten salt

In schools, molten potassium chlorate is used in screaming jelly babies, Gummy bear, Haribo, and Trolli candy demonstration where the candy is dropped into the molten salt.

In chemical labs it is used to oxidize HCl and release small amounts of gaseous chlorine.

Militant groups in Afghanistan also use potassium chlorate extensively as a key component in the production of improvised explosive devices (IEDs). When significant effort was made to reduce the availability of ammonium nitrate fertilizer in Afghanistan, IED makers started using potassium chlorate as a cheap and effective alternative. In 2013, 60% of IEDs in Afghanistan used potassium chlorate, making it the most common ingredient used in IEDs.[10] Potassium chlorate was also the main ingredient in the car bomb used in 2002 Bali bombings that killed 202 people.

Potassium chlorate is used to force the blossoming stage of the longan tree, causing it to produce fruit in warmer climates.[11]

Safety

[edit]

Potassium chlorate should be handled with care. It reacts vigorously, and in some cases spontaneously ignites or explodes, when mixed with many combustible materials. It burns vigorously in combination with virtually any combustible material, even those normally only slightly flammable (including ordinary dust and lint). Mixtures of potassium chlorate and a fuel can ignite by contact with sulfuric acid, so it should be kept away from this reagent. Sulfur should be avoided in pyrotechnic compositions containing potassium chlorate, as these mixtures are prone to spontaneous deflagration. Most sulfur contains trace quantities of sulfur-containing acids, and these can cause spontaneous ignition - "Flowers of sulfur" or "sublimed sulfur", despite the overall high purity, contains significant amounts of sulfur acids. Also, mixtures of potassium chlorate with any compound with ignition promoting properties, such as antimony(III) sulfide, are very dangerous to prepare, as they are extremely shock sensitive.

See also

[edit]

References

[edit]
  1. ^ a b c d e f g "potassium chlorate". Retrieved 9 July 2015.
  2. ^ Seidell, Atherton; Linke, William F. (1952). Solubilities of Inorganic and Organic Compounds. Van Nostrand. Retrieved 2014-05-29.
  3. ^ a b Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A22. ISBN 978-0-618-94690-7.
  4. ^ a b c "Potassium chlorate". Retrieved 14 February 2022.
  5. ^ Michael Chambers. "ChemIDplus - 3811-04-9 - VKJKEPKFPUWCAS-UHFFFAOYSA-M - Potassium chlorate - Similar structures search, synonyms, formulas, resource links, and other chemical information". Retrieved 9 July 2015.
  6. ^ a b Vogt, Helmut; Balej, Jan; Bennett, John E.; Wintzer, Peter; Sheikh, Saeed Akbar; Gallone, Patrizio (June 15, 2000). "Chlorine Oxides and Chlorine Oxygen Acids". In Ullmann (ed.). Ullmann's Encyclopedia of Industrial Chemistry. Wiley‐VCH Verlag. doi:10.1002/14356007.a06_483. ISBN 9783527303854.
  7. ^ Anne Marie Helmenstine, Ph.D. "Potassium Chlorate Synthesis (Substitute) Formula". About.com Education. Retrieved 9 July 2015.
  8. ^ a b Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
  9. ^ Daniel J. Wakin and Alan Cowell (March 13, 2013). "New Round of Voting Fails to Name a Pope". The New York Times. Retrieved March 13, 2013.
  10. ^ "Afghan bomb makers shifting to new explosives for IEDs". USAToday.com. June 25, 2013. Retrieved 2013-06-25.
  11. ^ Manochai, P.; Sruamsiri, P.; Wiriya-alongkorn, W.; Naphrom, D.; Hegele, M.; Bangerth, F. (February 12, 2005). "Year around off-season flower induction in longan (Dimocarpus longan, Lour.) trees by KClO3 applications: potentials and problems". Scientia Horticulturae. 104 (4). Department of Horticulture, Maejo University, Chiang Mai, Thailand; Department of Horticulture, Chiang Mai University, Chiang Mai, Thailand; Institute of Special Crops and Crop Physiology, University of Hohenheim, 70593 Stuttgart, Germany: 379–390. doi:10.1016/j.scienta.2005.01.004. Retrieved November 28, 2010.{{cite journal}}: CS1 maint: location (link)
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