Sodium thiosulfate - wikipedia Sodium thiosulfate Sodium thiosulfate Names IUPAC name Sodium thiosulfate Other names Sodium hyposulfite Hyposulphite of soda Identifiers CAS Number 7772 - 98 - 7 10102 - 17 - 7 ( pentahydrate ) 3D model ( JSmol ) Interactive image ChEBI CHEBI : 132112 ChemSpider 22885 ECHA InfoCard 100.028. 970 E number E539 ( acidity regulators,... ) PubChem CID 24477 RTECS number XN6476000 UNII L0IYT1O31N InChI InChI = 1S / 2Na. H2O3S2 / c ; ; 1 - 5 ( 2, 3 ) 4 / h ; ; ( H2, 1, 2, 3, 4 ) / q2 * + 1 ; / p - 2 Key : AKHNMLFCWUSKQB - UHFFFAOYSA - L InChI = 1 / 2Na. H2O3S2 / c ; ; 1 - 5 ( 2, 3 ) 4 / h ; ; ( H2, 1, 2, 3, 4 ) / q2 * + 1 ; / p - 2 Key : AKHNMLFCWUSKQB - NUQVWONBAM SMILES ( Na+ ). ( Na+ ). ( O - ) S ( ( O - ) ) ( = O ) = S Properties Chemical formula Na S O Molar mass 158.11 g / mol ( anhydrous ) 248.18 g / mol ( pentahydrate ) Appearance White crystals Odor Odorless Density 1.667 g / cm Melting point 48.3 ° C ( 118.9 ° F ; 321.4 K ) ( pentahydrate ) Boiling point 100 ° C ( 212 ° F ; 373 K ) ( pentahydrate, - 5H O decomposition ) Solubility in water 70.1 g / 100 mL ( 20 ° C ) 231 g / 100 mL ( 100 ° C ) Solubility negligible in alcohol Refractive index ( n ) 1.489 Structure Crystal structure monoclinic Hazards Safety data sheet External MSDS R - phrases ( outdated ) R35 NFPA 704 0 0 Flash point Non-flammable Except where otherwise noted, data are given for materials in their standard state ( at 25 ° C ( 77 ° F ), 100 kPa ). N verify ( what is ? ) Infobox references Sodium thiosulfate ( sodium thiosulphate ) is a chemical and medication. As a medication it is used to treat cyanide poisoning and pityriasis versicolor. It is an inorganic compound with the formula Na S O xH O. Typically it is available as the white or colorless pentahydrate, Na S O 5 H O. The solid is an efflorescent ( loses water readily ) crystalline substance that dissolves well in water. It is also called sodium hyposulfite or `` hypo ''. It is on the World Health Organization 's List of Essential Medicines, the most effective and safe medicines needed in a health system. Contents 1 Uses 1.1 Medical uses 1.2 Iodometry 1.3 Photographic processing 1.4 Gold extraction 1.5 Neutralizing chlorinated water 1.6 Other 2 Structure 3 Production 4 Principal reactions 4.1 Aluminium cation reaction 4.2 Organic chemistry 5 References Uses Medical uses Main article : Sodium thiosulfate ( medical use ) It is used as an antidote to cyanide poisoning. Thiosulfate serves as a sulfur donor for the conversion of cyanide to thiocyanate ( which can then be safely excreted in the urine ), catalyzed by the enzyme rhodanase. For this purpose it is used together with sodium nitrite. It has been used as treatment of calciphylaxis in hemodialysis people with end - stage kidney disease. There is apparently an incompletely understood phenomenon whereby this causes severe metabolic acidosis in some patients. In foot baths for prophylaxis of ringworm, and as a topical antifungal agent for tinea versicolor. It is used in the management of extravasations during chemotherapy. Sodium thiosulfate prevents alkylation and tissue destruction by providing a substrate for the alkylating agents that have invaded the subcutaneous tissues. The dose may be 2 ml of 0.17 M ( a solution of 4 ml 10 % sodium thiosulfate and 6 ml sterile water for injection ). It may be instilled subcutaneously into multiple sites using a small - gauge needle. Data are limited on this method with few recommendations. In measuring the volume of extracellular body fluid and the renal glomerular filtration rate. Sodium Thiosulfate can be used to neutralize and ameliorate renal toxicity of the chemotherapeutic agent Cisplatin Iodometry In analytical chemistry, the most important use comes because the thiosulfate anion reacts stoichiometrically with iodine in aqueous solution, reducing it to iodide as it is oxidized to tetrathionate : 2 S O + I → S O + 2 I Due to the quantitative nature of this reaction, as well as because Na S O 5H O has an excellent shelf - life, it is used as a titrant in iodometry. Na S O 5H O is also a component of iodine clock experiments. This particular use can be set up to measure the oxygen content of water through a long series of reactions in the Winkler test for dissolved oxygen. It is also used in estimating volumetrically the concentrations of certain compounds in solution ( hydrogen peroxide, for instance ) and in estimating the chlorine content in commercial bleaching powder and water. Photographic processing Silver halides, e.g., AgBr, typical components of photographic emulsions, dissolve upon treatment with aqueous thiosulfate : 2 S O + AgBr → ( Ag ( S O ) ) + Br This application as a photographic fixer was discovered by John Herschel. It is used for both film and photographic paper processing ; the sodium thiosulfate is known as a photographic fixer, and is often referred to as ' hypo ', from the original chemical name, hyposulphite of soda. Gold extraction Sodium thiosulfate is a component of an alternative lixiviant to cyanide for extraction of gold. However, it forms a strong soluble complex with gold ( I ) ions, ( Au ( S O ) ). The advantage of this approach is that thiosulfate is essentially not toxic and that ore types that are refractory to gold cyanidation ( e.g. carbonaceous or Carlin - type ores ) can be leached by thiosulfate. Some problems with this alternative process include the high consumption of thiosulfate, and the lack of a suitable recovery technique, since ( Au ( S O ) ) does not adsorb to activated carbon, which is the standard technique used in gold cyanidation to separate the gold complex from the ore slurry. Neutralizing chlorinated water It is used to dechlorinate tap water including lowering chlorine levels for use in aquaria and swimming pools and spas ( e.g., following superchlorination ) and within water treatment plants to treat settled backwash water prior to release into rivers. The reduction reaction is analogous to the iodine reduction reaction. In pH testing of bleach substances, sodium thiosulfate neutralizes the color - removing effects of bleach and allows one to test the pH of bleach solutions with liquid indicators. The relevant reaction is akin to the iodine reaction : thiosulfate reduces the hypochlorite ( active ingredient in bleach ) and in so doing becomes oxidized to sulfate. The complete reaction is : 4 NaClO + Na S O + 2 NaOH → 4 NaCl + 2 Na SO + H O Similarly, sodium thiosulfate reacts with bromine, removing the free bromine from solution. Solutions of sodium thiosulfate are commonly used as a precaution in chemistry laboratories when working with bromine and for the safe disposal of bromine, iodine, or other strong oxidizers. Other This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. ( November 2013 ) Sodium thiosulfate is also used : As a component in hand warmers and other chemical heating pads that produce heat by exothermic crystallization of a supercooled solution. In bacteriological water assessment, as it promotes the survival of coliform organisms by neutralizing residual chlorine. In the tanning of leather To demonstrate the concept of supercooling in physics classes : Sodium thiosulfate, when heated, dissolves in its own water of crystallisation. This solution can be cooled to room temperature without recrystallisation. When crystallisation is induced by the addition of a small seed crystal, the sudden temperature rise can be experienced by touch. As part of patina recipes for copper alloys Often used in pharmaceutical preparations as an anionic surfactant to aid in dispersion Structure Two polymorphs are known of the pentahydrate. The anhydrous salt exists in several polymorphs. In the solid state, the thiosulfate anion is tetrahedral in shape and is notionally derived by replacing one of the oxygen atoms by a sulfur atom in a sulfate anion. The S-S distance indicates a single bond, implying that the terminal sulfur bears significant negative charge and the S-O interactions have more double - bond character. Production On an industrial scale, sodium thiosulfate is produced chiefly from liquid waste products of sodium sulfide or sulfur dye manufacture. In the laboratory, this salt can be prepared by heating an aqueous solution of sodium sulfite with sulfur or by boiling aqueous sodium hydroxide and sulfur according to this equation : 6 NaOH + 4 S → 2 Na S + Na S O + 3 H O Principal reactions Upon heating to 300 ° C, it decomposes to sodium sulfate and sodium polysulfide : 4 Na S O → 3 Na SO + Na S Thiosulfate salts characteristically decompose upon treatment with acids. Initial protonation occurs at sulfur. When the protonation is conducted in diethyl ether at − 78 ° C, H S O ( thiosulfuric acid ) can be obtained. It is a somewhat strong acid with pK s of 0.6 and 1.7 for the first and second dissociations, respectively. Under normal conditions, acidification of solutions of this salt excess with even dilute acids results in complete decomposition to sulfur, sulfur dioxide, and water : Na S O + 2 HCl → 2 NaCl + S + SO + H O This reaction is known as a `` clock reaction '', because when the sulfur reaches a certain concentration, the solution turns from colourless to a pale yellow. This reaction has been employed to generate colloidal sulfur. This process is used to demonstrate the concept of reaction rate in chemistry classes. Aluminium cation reaction Sodium thiosulfate is also used in analytical chemistry. It can, when heated with a sample containing aluminium cations, produce a white precipitate : 2 Al + 3 S O + 3 H O → 3 SO + 3 S + 2 Al ( OH ) Organic chemistry Alkylation of sodium thiosulfate gives S - alkylthiosulfates, which are called Bunte salts. This reaction is employed in one synthesis of the industrial reagent thioglycolic acid : ClCH CO H + Na S O → Na ( O S CH CO H ) + NaCl Na ( O S CH CO H ) + H O → HSCH CO H + NaHSO References Jump up ^ Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health ^ Jump up to : WHO Model Formulary 2008 ( PDF ). World Health Organization. 2009. p. 66. ISBN 9789241547659. Retrieved 8 January 2017. ^ Jump up to : J.J. Barbera, A. Metzger, M. Wolf `` Sulfites, Thiosulfates, and Dithionites '' in Ullmann 's Encyclopedia of Industrial Chemistry 2012, Wiley - VCH, Weinheim. doi : 10.1002 / 14356007. a25_477 Jump up ^ `` WHO Model List of Essential Medicines ( 19th List ) '' ( PDF ). World Health Organization. April 2015. Retrieved 8 December 2016. Jump up ^ `` Toxicity, Cyanide : Overview - eMedicine ''. Retrieved 2009 - 01 - 01. Jump up ^ Hall AH, Dart R, Bogdan G ( June 2007 ). `` Sodium thiosulfate or hydroxocobalamin for the empiric treatment of cyanide poisoning ? ''. Ann Emerg Med. 49 ( 6 ) : 806 -- 13. PMID 17098327. doi : 10.1016 / j. annemergmed. 2006.09. 021. Jump up ^ Cicone JS, Petronis JB, Embert CD, Spector DA ( June 2004 ). `` Successful treatment of calciphylaxis with intravenous sodium thiosulfate ''. Am. J. Kidney Dis. 43 ( 6 ) : 1104 -- 8. PMID 15168392. doi : 10.1053 / j. ajkd. 2004.03. 018. Jump up ^ http://www.medscape.com/viewarticle/762244 Jump up ^ Selk N, Rodby RA ( Jan -- Feb 2011 ). `` Unexpectedly severe metabolic acidosis associated with sodium thiosulfate therapy in a patient with calcific uremic arteriolopathy ''. Semin. Dial. 24 ( 1 ) : 85 -- 8. PMID 21338397. doi : 10.1111 / j. 1525 - 139X. 2011.00848. x. Jump up ^ `` Sodium thiosulfate '' at Dorland 's Medical Dictionary Jump up ^ Journal of Pharmacology and Experimental Therapeutics ( 9 / 2005 ). `` Protection against cisplatin - induced toxicities by N - acetylcysteine and sodium thiosulfate as assessed at the molecular, cellular, and in vivo levels. '' : 1052 -- 8. PMID 15951398. Check date values in : access - date =, date = ( help ) ; access - date = requires url = ( help ) Jump up ^ Charles Robert Gibson ( 1908 ). The Romance of Modern Photography, Its Discovery & Its Achievements. Seeley & Co. p. 37. Jump up ^ Aylmore MG, Muir DM ( 2001 ). `` Thiosulfate Leaching of Gold - a Review ''. Minerals Engineering. 14 : 135 -- 174. doi : 10.1016 / s0892 - 6875 ( 00 ) 00172 - 2. Jump up ^ Ralph E. Noble ; Oscar Gullans ( August 1955 ). `` Influence of sodium thiosulfate on the survival of coliform organisms in stored samples of untreated lake water ''. Journal of Bacteriology. 70 ( 2 ) : 249 -- 50. PMC 357669. PMID 13251993. Jump up ^ The Public Health Laboratory Service Water Sub-Committee ( December 1953 ). `` The effect of sodium thiosulphate on the coliform and Bacterium coli counts of non-chlorinated water samples ''. The Journal of Hygiene. 51 ( 4 ) : 572 -- 7. PMC 2217764. PMID 13118158. doi : 10.1017 / s0022172400036858. ^ Jump up to : Holleman, A.F. ; Wiberg, E. `` Inorganic Chemistry '' Academic Press : San Diego, 2001. ISBN 0 - 12 - 352651 - 5 Jump up ^ Gordin, H.M. ( 1913 ). Elementary Chemistry, Volume I. Inorganic Chemistry. Chicago : Medico - Dental Publishing Co. pp. 162 & 287 -- 288. Wikimedia Commons has media related to Sodium thiosulfate. Sodium compounds NaAlO NaBH NaBH ( CN ) NaBO NaBiO NaBr NaBrO NaBrO NaCH COO NaC H CO NaC H ( OH ) CO NaCN NaCl NaClO NaClO NaClO NaClO NaF Na FeO NaH NaHCO NaH PO NaHSO NaHSO NaI NaIO NaIO Na IO NaMnO NaN NaNH NaNO NaNO NaOCN NaO NaO NaOH NaPO H NaReO NaSCN NaSH NaTcO NaVO Na CO Na C O Na CrO Na Cr O Na GeO Na MnO Na MnO Na MoO Na MoS Na N O Na O Na O Na O ( UO ) Na PO F Na S Na SO Na SO Na S O Na S O Na S O Na S O Na S O Na S O Na S O Na Se Na SeO Na SeO Na SiO Na Si O Na SiO Na Te Na TeO Na TeO Na Po Na Ti O Na U O NaWO Na Zn ( OH ) Na N Na P Na PO Na VO Na Fe ( CN ) Na P O Na P O Chemical formulas Antifungals ( D01 and J02 ) Wall / membrane Ergosterol inhibitors Azoles ( lanosterol 14α - demethylase inhibitors ) Imidazoles Topical : bifonazole butoconazole chlormidazole clotrimazole croconazole eberconazole econazole fenticonazole flutrimazole isoconazole ketoconazole luliconazole miconazole neticonazole omoconazole oxiconazole sertaconazole sulconazole tioconazole Systemic : ketoconazole Triazoles Topical : efinaconazole fluconazole fosfluconazole terconazole Systemic : fluconazole hexaconazole isavuconazole itraconazole posaconazole voriconazole Unknown : albaconazole ravuconazole Thiazoles Topical : abafungin Polyene antimycotics ( ergosterol binding ) Topical : hamycin natamycin nystatin Systemic : amphotericin B, hamycin Squalene monooxygenase inhibitors Allylamines Topical : naftifine terbinafine Systemic : terbinafine Benzylamines Topical : butenafine Others Topical : amorolfine β - glucan synthase inhibitors echinocandins ( anidulafungin biafungin caspofungin cilofungin micafungin ) Intracellular Pyrimidine analogues / thymidylate synthase inhibitors flucytosine Mitotic inhibitors griseofulvin Aminoacyl tRNA synthetase inhibitors tavaborole Others bromochlorosalicylanilide chlorophetanol chlorphenesin ciclopirox crystal violet dimazole ethylparaben haloprogin polynoxylin potassium iodide salicylic acid selenium disulfide sodium thiosulfate sulbentine taurolidine ticlatone tolciclate tolnaftate tribromometacresol undecylenic acid Whitfield 's ointment citronella oil lemon grass lemon myrtle orange oil patchouli tea tree oil PCP : atovaquone dapsone pentamidine WHO - EM Withdrawn from market Clinical trials : Phase III Never to phase III Antidotes ( V03AB ) Nervous system Nerve agent / Organophosphate poisoning Atropine Biperiden Diazepam Oximes Obidoxime Pralidoxime see also : Cholinesterase Barbiturate overdose Bemegride Ethamivan Benzodiazepine overdose Cyprodenate Flumazenil GHB overdose Physostigmine SCH - 50911 Opioid overdose Diprenorphine Doxapram Nalmefene Nalorphine Naloxone Naltrexone Reversal of neuromuscular blockade Sugammadex Circulatory system Beta blocker Glucagon Digoxin toxicity Digoxin Immune Fab Heparin Protamine Other Arsenic poisoning Dimercaprol Succimer Cyanide poisoning 4 - Dimethylaminophenol Hydroxocobalamin nitrite Amyl nitrite Sodium nitrite Sodium thiosulfate Hydrofluoric acid Calcium gluconate Methanol / Ethylene glycol poisoning Primary alcohols : Ethanol Fomepizole Paracetamol toxicity ( Acetaminophen ) Acetylcysteine Glutathione Methionine Toxic metals ( cadmium lead mercury thallium ) Dimercaprol Edetates Prussian blue Other iodine - 131 Potassium iodide Methylthioninium chloride oxidizing agent Potassium permanganate Prednisolone / promethazine Emetic Copper sulfate Ipecacuanha Syrup of ipecac WHO - EM Withdrawn from market Clinical trials : Phase III Never to phase III Retrieved from `` https://en.wikipedia.org/w/index.php?title=Sodium_thiosulfate&oldid=802517912 '' Categories : Thiosulfates Sodium compounds Photographic chemicals Antidotes Antifungals for dermatologic use Orphan drugs Specialty drugs Hidden categories : CS1 errors : dates Pages using citations with accessdate and no URL Chemical articles with multiple compound IDs Multiple chemicals in an infobox that need indexing Chemical articles with multiple CAS registry numbers Articles without KEGG source Articles with changed CASNo identifier Articles with changed EBI identifier ECHA InfoCard ID from Wikidata E number from Wikidata Chembox having DSD data Articles containing unverified chemical infoboxes All articles with unsourced statements Articles with unsourced statements from June 2010 Articles needing additional references from November 2013 All articles needing additional references Articles with unsourced statements from September 2014 Talk Contents About Wikipedia Bosanski Català Čeština Dansk Deutsch Español Esperanto فارسی Français Gaeilge 한국어 Հայերեն Bahasa Indonesia Italiano עברית Қазақша Latviešu Magyar Bahasa Melayu Nederlands 日本 語 Polski Português Română Русский Slovenčina Slovenščina Српски / srpski Srpskohrvatski / српскохрватски Suomi Svenska தமிழ் Українська Tiếng Việt 中文 Edit links This page was last edited on 26 September 2017, at 17 : 31. 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Question: why sodium thiosulphate is known as hypo solution
Answer: from the original chemical name, hyposulphite of soda