Potassium thiosulfate: Difference between revisions
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'''Potassium thiosulfate''', commonly abbreviated '''KTS''', is |
'''Potassium thiosulfate''', commonly abbreviated '''KTS''', is an [[inorganic compound]] with the formula K<sub>2</sub>S<sub>2</sub>O<sub>3</sub>. This salt can form multiple hydrates, such as the monohydrate, dihydrate, and the pentahydrate, all of which are white or colorlesss.<ref name="soln" /> It is used as a [[fertilizer]]. Potassium thiosulfate is produced by reacting [[potassium hydroxide]] with [[ammonium hydroxide]], [[sulfur dioxide]], and elemental [[sulfur]].<ref name=":)">{{cite book |editor1-last=Sulewski |editor1-first=Gavin |editor2-last=Thompson |editor2-first=Michael |editor3-last=Mikkelsen |editor3-first=Robert |editor4-last=Norton |editor4-first=Robert |editor5-last=Scott |editor5-first=T. |title=Improving Potassium Recommendations for Agricultural Crops |date=2020 |publisher=Springer International Publishing |isbn=9783030591977 |page=60 |url=https://www.google.com/books/edition/Improving_Potassium_Recommendations_for/pfsOEAAAQBAJ?hl=en&gbpv=0 |access-date=6 October 2021 |language=English |format=Ebook}}</ref> |
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==Formation and reactions== |
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==Properties== |
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{{main|thiosulfate}} |
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This compound is pH sensitive, it is unstable at pH below 5.5 and above 8.5.<ref name="fert">{{cite book |author1=Western Plant Health Association |editor1-last=Barlow |editor1-first=Dave |editor2-last=Pier |editor2-first=Jerome |title=Western Fertilizer Handbook |date=2018 |publisher=Waveland Press |isbn=9781478638841 |page=186 |edition=Third Horticulture |url=https://www.google.com/books/edition/Western_Fertilizer_Handbook/BHeCDwAAQBAJ?hl=en&gbpv=0 |access-date=6 October 2021 |language=English |format=Ebook}}</ref> The thiosulfate oxidizes to form sulfate ions during an acid-forming process, because of this, it can [[chelation|sequester]] metals, especially [[iron]].<ref name=":)" /> |
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Thiosulfate salts are produced by the reaction of [[sulfite]] ion with elemental sulfur, and by incomplete oxidation of [[sulfide]]s. Thiosulfates are stable in neutral or [[alkali]]ne solutions, but not in acidic solutions, due to [[disproportionation]] to sulfur dioxide and sulfur:<ref name="Ullmann">{{Ullmann|authors=Barbera, J. J.; Metzger, A.; Wolf, M.|title=Sulfites, Thiosulfates, and Dithionites|doi=10.1002/14356007.a25_477|isbn=9783527306732|date=2012}}</ref> |
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:{{chem|S|2|O|3|2−}} + 2 H<sup>+</sup> → SO<sub>2</sub> + "S" + H<sub>2</sub>O |
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Thiosulfate reacts with iodine to give [[tetrathionate]]: |
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:2 {{chem|S|2|O|3|2−}} + I<sub>2</sub> → {{chem|S|4|O|6|2−}} + 2 I<sup>−</sup> |
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Thiosulfate extensively forms diverse complexes with [[transition metal]]s. In the era of silver-based photography, thiosulfate was consumed on a large scale as a "stop" reagent. This application exploits thiosulfate's ability to dissolve silver halides. Thiosulfate is also used to extract or leach gold (sodium thiosulfate) and silver from their ores as a less toxic alternative to cyanide.<ref name="Ullmann">{{Ullmann|authors=Barbera, J. J.; Metzger, A.; Wolf, M.|title=Sulfites, Thiosulfates, and Dithionites|doi=10.1002/14356007.a25_477|isbn=9783527306732|date=2012}}</ref> |
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==Uses== |
==Uses== |
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Potassium thiosulfate is commonly used as a fertilizer alone or with [[urea]] and/or [[urea ammonium nitrate]]<ref name="fert" /> due to its ability to delay [[nitrification]] thus has the ability to reduce the emission of [[nitrous oxide]].<ref>{{cite journal |author1=Zejiang Cai |author2=Suduan Gao |author3=Minggang Xu |author4=Bradley D Hanson |title=Evaluation of potassium thiosulfate as a nitrification inhibitor to reduce nitrous oxide emissions |date=2017 |doi=10.1016/j.scitotenv.2017.10.274 |pmid=29128773 |language=English}}</ref> It can also reduce the amount of [[fumigants]] being released from the soil.<ref>{{cite journal |author1=Ruijun Qin |author2=Suduan Gao |author3=Jason A McDonald |author4=Husein Ajwa |author5=Shachar Shem-Tov |author6=David A Sullivan |title=Effect of plastic tarps over raised-beds and potassium thiosulfate in furrows on chloropicrin emissions from drip fumigated fields |date=2008 |volume=72 |issue=4 |pages=558-563 |doi=10.1016/j.chemosphere.2008.03.023 |pmid=18440581 |language=English}}</ref> If used alone it is used in very dilute solution due to its ability to cause [[phytotoxicity]] symptoms. This is caused by the elemental sulfur being oxidized to produce [[sulfuric acid]].<ref name="fert" /> |
Potassium thiosulfate is commonly used as a fertilizer alone or with [[urea]] and/or [[urea ammonium nitrate]]<ref name="fert">{{cite book |author1=Western Plant Health Association |editor1-last=Barlow |editor1-first=Dave |editor2-last=Pier |editor2-first=Jerome |title=Western Fertilizer Handbook |date=2018 |publisher=Waveland Press |isbn=9781478638841 |page=186 |edition=Third Horticulture |url=https://www.google.com/books/edition/Western_Fertilizer_Handbook/BHeCDwAAQBAJ?hl=en&gbpv=0 |access-date=6 October 2021 |language=English |format=Ebook}}</ref> The thiosulfate oxidizes to form sulfate ions during an acid-forming process, because of this, it can [[chelation|sequester]] metals, especially [[iron]].<ref name=":)" />due to its ability to delay [[nitrification]]. It thus has the ability to reduce the emission of [[nitrous oxide]].<ref>{{cite journal |author1=Zejiang Cai |author2=Suduan Gao |author3=Minggang Xu |author4=Bradley D Hanson |title=Evaluation of potassium thiosulfate as a nitrification inhibitor to reduce nitrous oxide emissions |date=2017 |doi=10.1016/j.scitotenv.2017.10.274 |pmid=29128773 |language=English}}</ref> It can also reduce the amount of [[fumigants]] being released from the soil.<ref>{{cite journal |author1=Ruijun Qin |author2=Suduan Gao |author3=Jason A McDonald |author4=Husein Ajwa |author5=Shachar Shem-Tov |author6=David A Sullivan |title=Effect of plastic tarps over raised-beds and potassium thiosulfate in furrows on chloropicrin emissions from drip fumigated fields |date=2008 |volume=72 |issue=4 |pages=558-563 |doi=10.1016/j.chemosphere.2008.03.023 |pmid=18440581 |language=English}}</ref> If used alone it is used in very dilute solution due to its ability to cause [[phytotoxicity]] symptoms. This is caused by the elemental sulfur being oxidized to produce [[sulfuric acid]].<ref name="fert" /> |
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==References== |
==References== |
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Revision as of 17:22, 8 October 2021
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| File:Potassium-thiosulfate-3D-balls-ionic.png | |
| Names | |
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Other names
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| Identifiers | |
3D model (JSmol)
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| ECHA InfoCard | 100.030.593 |
| EC Number |
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PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| K2S2O3 | |
| Molar mass | 190.32 g/mol |
| Appearance | White solid |
| Density | 2.37 g/cm3 |
| 96.1 g/100 ml (0 °C) 155.4 g/100 ml (20 °C) 165 g/100 ml (25 °C) 175.7 g/100 ml (30 °C) 204.7 g/100 ml (40 °C) 215.2 g/100 ml (50 °C) 238.3 g/100 ml (60 °C) 255.2 g/100 ml (70 °C) 293.1 g/100 ml (80 °C) 312 g/100 ml (90 °C)[1] | |
| Hazards | |
| GHS labelling: | |
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| Warning | |
| H315, H319 | |
| P264, P280, P302+P352, P305+P351+P338, P321, P332+P313, P337+P313, P362 | |
| Related compounds | |
Other cations
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Sodium thiosulfate |
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 thiosulfate, commonly abbreviated KTS, is an inorganic compound with the formula K2S2O3. This salt can form multiple hydrates, such as the monohydrate, dihydrate, and the pentahydrate, all of which are white or colorlesss.[1] It is used as a fertilizer. Potassium thiosulfate is produced by reacting potassium hydroxide with ammonium hydroxide, sulfur dioxide, and elemental sulfur.[2]
Formation and reactions
Thiosulfate salts are produced by the reaction of sulfite ion with elemental sulfur, and by incomplete oxidation of sulfides. Thiosulfates are stable in neutral or alkaline solutions, but not in acidic solutions, due to disproportionation to sulfur dioxide and sulfur:[3]
- S
2O2−
3 + 2 H+ → SO2 + "S" + H2O
Thiosulfate reacts with iodine to give tetrathionate:
- 2 S
2O2−
3 + I2 → S
4O2−
6 + 2 I−
Thiosulfate extensively forms diverse complexes with transition metals. In the era of silver-based photography, thiosulfate was consumed on a large scale as a "stop" reagent. This application exploits thiosulfate's ability to dissolve silver halides. Thiosulfate is also used to extract or leach gold (sodium thiosulfate) and silver from their ores as a less toxic alternative to cyanide.[3]
Uses
Potassium thiosulfate is commonly used as a fertilizer alone or with urea and/or urea ammonium nitrate[4] The thiosulfate oxidizes to form sulfate ions during an acid-forming process, because of this, it can sequester metals, especially iron.[2]due to its ability to delay nitrification. It thus has the ability to reduce the emission of nitrous oxide.[5] It can also reduce the amount of fumigants being released from the soil.[6] If used alone it is used in very dilute solution due to its ability to cause phytotoxicity symptoms. This is caused by the elemental sulfur being oxidized to produce sulfuric acid.[4]
References
- ^ a b Atherton Seidell (1919). Solubilities of inorganic and organic compounds c. 2. D. Van Nostrand Company. p. 568.
- ^ a b Sulewski, Gavin; Thompson, Michael; Mikkelsen, Robert; Norton, Robert; Scott, T., eds. (2020). Improving Potassium Recommendations for Agricultural Crops (Ebook). Springer International Publishing. p. 60. ISBN 9783030591977. Retrieved 6 October 2021.
- ^ a b "Sulfites, Thiosulfates, and Dithionites". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. 2012. doi:10.1002/14356007.a25_477. ISBN 9783527306732.
{{cite encyclopedia}}: Unknown parameter|authors=ignored (help) - ^ a b Western Plant Health Association (2018). Barlow, Dave; Pier, Jerome (eds.). Western Fertilizer Handbook (Ebook) (Third Horticulture ed.). Waveland Press. p. 186. ISBN 9781478638841. Retrieved 6 October 2021.
- ^ Zejiang Cai; Suduan Gao; Minggang Xu; Bradley D Hanson (2017). "Evaluation of potassium thiosulfate as a nitrification inhibitor to reduce nitrous oxide emissions". doi:10.1016/j.scitotenv.2017.10.274. PMID 29128773.
{{cite journal}}: Cite journal requires|journal=(help) - ^ Ruijun Qin; Suduan Gao; Jason A McDonald; Husein Ajwa; Shachar Shem-Tov; David A Sullivan (2008). "Effect of plastic tarps over raised-beds and potassium thiosulfate in furrows on chloropicrin emissions from drip fumigated fields". 72 (4): 558–563. doi:10.1016/j.chemosphere.2008.03.023. PMID 18440581.
{{cite journal}}: Cite journal requires|journal=(help)