Sodium Thiosulfate Pentahydrate, Reagent, 99.5+%, 150g

US $28.00

Tallinn, Estonia
Jan 30th

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Sodium thiosulfate pentahydrate, reagent, 99.5+%, 150g CAS Number: 10102-17-7 Linear Formula: Na2S2O3·5H2O Molecular Weight: 248.18 Sodium thiosulfate is a colorless crystalline compound that is more familiar as the pentahydrate, Na2S2O3·5H2O, an efflorescent, monoclinic crystalline substance also called sodium hyposulfite or “hypo.” 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 sulfur bears significant negative charge and the S-O interactions have more double bond character. The first protonation of thiosulfate occurs at sulfur. Sodium thiosulfate is used: As a component in hand warmers and other chemical heating pads that produce heat by exothermic crystallization of a supercooled solution. In bleach In pH testing of bleach substances. The universal indicator and any other liquid pH indicators are destroyed by bleach, rendering them useless for testing the pH. If one first adds sodium thiosulfate to such solutions, it will neutralize the color-removing effects of bleach and allow 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 + Na2S2O3 + 2 NaOH -> 4 NaCl + 2 Na2SO4 + H2O To dechlorinate tap water for aquariums or treat effluent from waste water treatments prior to release into rivers. The reduction reaction is analogous to the iodine reduction reaction. Treatment of tap water requires between 0.1 grams and 0.3 grams of pentahydrated (crystalline) sodium thiosulfate per 10 liters of water. To lower chlorine levels in swimming pools and spas following super chlorination. To remove iodine stains, e.g. after the explosion of nitrogen triiodide. Similarly, sodium thiosulfate reacts with bromine to render harmless products. 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. 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 reaction rate in chemistry classes. The thiosulfate ion can decompose into the sulfite ion and a colloidal suspension of sulfur, which is opaque. The equation for this acid-catalysed reaction is as follows: S2O32–(aq) -> SO32–(aq) + S(s) To demonstrate the concept of supercooling in physics classes. Melted sodium thiosulfate is very easy to overcool to room temperature and when crystallization is forced, the sudden temperature jump to 48.3 °C 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. It can also be used as a very interesting solute in supersaturation experiments. As an ingredient to table salt, e.g. Sysco Corporation's small packets of Iodized Salt