Sodium selenite 2851992 223225406 2008-07-03T03:39:25Z Smokefoot 698909 Reverted edits by [[Special:Contributions/206.192.172.22|206.192.172.22]] ([[User talk:206.192.172.22|talk]]) to last version by 76.27.87.11 {{Chembox new |ImageFile= |ImageSize= |IUPACName= |OtherNames= |Section1= {{Chembox Identifiers | CASNo=10102-18-8 | PubChem=24934 | SMILES=[O-][Se](=O)[O-].[Na+].[Na+] }} |Section2= {{Chembox Properties | Formula=Na2SeO3 | MolarMass=172.938 | Appearance= | Density= | MeltingPt= | BoilingPt= | Solubility= }} |Section3= {{Chembox Hazards | MainHazards= | FlashPt= | Autoignition= }} }} '''Sodium selenite''' is a [[chemical compound]] with the [[chemical formula|formula]] [[Sodium|Na]]<sub>2</sub>[[Selenium|Se]][[Oxygen|O]]<sub>3</sub>. This salt is the most common water soluble forms of selenium. The industrial production of selenium often involves the extraction of sodium selenite from residues obtained during the purification of copper metal. Acidification of solutions of sodium selenite followed by reduction with sulfur dioxide gives elemental selenium. ==Synthesis and fundamental reactions== The salt is usually prepared by hydrolysis of [[selenium dioxide]]: :SeO<sub>2</sub> + 2 NaOH → Na<sub>2</sub>SeO<sub>3</sub> + H<sub>2</sub>O Acidification gives selenous acid, which, unlike sulfurous acid, is isolable.<ref>Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.</ref> Akin to the related salt sodium sulfite, Na<sub>2</sub>SeO<sub>3</sub> features a pyramidal dianion SeO<sub>3</sub><sup>2-</sup> with C<sub>3v</sub> symmetry. Oxidation of this anion give sodium selenate, Na<sub>2</sub>SeO<sub>4</sub>. ==Applications== Together with the related barium and zinc salts, sodium selenite is mainly used in the manufacture of colorless glass. Its pink coloration cancels out the green color imparted by iron impurities.<ref>Bernd E. Langner "Selenium and Selenium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. {{doi|10.1002/14356007.a23_525}} Article Online Posting Date: June 15, 2000</ref> ==Safety== Selenium is an essential element (animals require selenium for selenium-dependent enzymes such as [[glutathione peroxidase]].<ref>[http://lpi.oregonstate.edu/infocenter/minerals/selenium/ Linus Pauling Institute at Oregon State University] lpi.oregonstate.edu</ref>). Sodium selenite is currently used in some food supplements in microgram quantities, but it is toxic at higher levels. See [[MSDS]]. ==References== <references/> ==External links== * [http://lpi.oregonstate.edu/infocenter/minerals/selenium/ Linus Pauling Institute page on selenium] {{Mineral supplements}} [[Category:Selenites]] [[Category:Sodium compounds]] [[Category:Dietary minerals]] [[Category:Dietary supplements]] [[ar:سيلينيت صوديوم]] [[de:Natriumselenit]] [[fr:Sélénite de sodium]] [[ja:亜セレン酸ナトリウム]]