Sodium selenite
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3D model (
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ChEBI | |
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ChemSpider | |
ECHA InfoCard
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100.030.230 |
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KEGG | |
PubChem CID
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RTECS number
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UNII |
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UN number | 2630 |
CompTox Dashboard (EPA)
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Properties | |
Na2O3Se | |
Molar mass | 172.948 g·mol−1 |
Appearance | colourless solid |
Density | 3.1 g/cm3 |
Melting point | decomposes at 710 °C |
85 g/100 mL (20 °C) | |
Solubility | insoluble in ethanol |
Structure | |
tetragonal | |
Pharmacology | |
A12CE02 (WHO) (Oral), B05XA20 (WHO) (Parenteral) | |
Hazards | |
GHS labelling: | |
Danger | |
H300, H317, H331, H411 | |
P261, P264, P270, P271, P272, P273, P280, P301+P310, P302+P352, P304+P340, P311, P321, P330, P333+P313, P363, P391, P403+P233, P405, P501 | |
NFPA 704 (fire diamond) | |
Safety data sheet (SDS) | ICSC 0698 |
Related compounds | |
Related compounds
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sodium biselenite
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sodium selenite is the inorganic compound with the formula Na2SeO3. This salt is a colourless solid. The pentahydrate Na2SeO3(H2O)5 is the most common water-soluble selenium compound.
Synthesis and fundamental reactions
Sodium selenite usually is prepared by the reaction of selenium dioxide with sodium hydroxide:[1]
- SeO2 + 2 NaOH → Na2SeO3 + H2O
The hydrate converts to the anhydrous salt upon heating to 40 °C.
According to X-ray crystallography, both anhydrous Na2SeO3 and its pentahydrate feature pyramidal SeO32−. The Se-O distances range from 1.67 to 1.72 Å.[2] Oxidation of this anion gives sodium selenate, Na2SeO4.[3]
Applications
Together with the related barium and zinc selenites, sodium selenite is mainly used in the manufacture of colorless glass. The pink color imparted by these selenites cancels out the green color imparted by iron impurities.[4]
Because selenium is an
The US Food and Drug Administration approved a selenium supplement to animal diets; the most common form is sodium selenite for pet foods. According to one article, "not much was known about which selenium compounds to approve for use in animal feeds when the decisions were made back in the 1970s .. At the time the regulatory action was taken, only the inorganic selenium salts (sodium selenite and sodium selenate) were available at a cost permitting their use in animal feed.” [5]
Sodium selenite has been proposed as an effective suicide agent.[6]
Safety
Selenium is toxic in high concentrations. As sodium selenite, the
See also
References
- ^ F. Féher, "Sodium Selenite" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 432.
- ISSN 1600-5368.
- PMID 24454013.
- S2CID 12668227.
- OCLC 1003529499.)
{{cite book}}
: CS1 maint: location missing publisher (link - PMID 6998645.
- PMID 25077263.
- ^ Tolerable Upper Intake Levels For Vitamins And Minerals (PDF), European Food Safety Authority, 2006