What is Sodium selenite?
{{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 464403878 | ImageFile = Sodium selenite.ვკ.jpg | ImageSize = | IUPACName = | OtherNames = |Section1={{Chembox Identifiers | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 23308 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = HIW548RQ3W | InChI = 1/2Na.H2O3Se/c;;1-4(2)3/h;;(H2,1,2,3)/q2*+1;/p-2 | InChIKey = BVTBRVFYZUCAKH-NUQVWONBAC | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 48843 | SMILES = [Na+].[Na+].[O-][Se]([O-])=O | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/2Na.H2O3Se/c;;1-4(2)3/h;;(H2,1,2,3)/q2*+1;/p-2 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = BVTBRVFYZUCAKH-UHFFFAOYSA-L | CASNo = 10102-18-8 (hydrate: 26970-82-1) | CASNo_Ref = {{cascite|changed|CAS}} | ChEMBL_Ref = {{ebicite|correct|EBI}} | ChEMBL = 112302 | PubChem = 24934 | EINECS = 233-267-9 | RTECS = VS7350000 | UNNumber = 2630 | KEGG_Ref = {{keggcite|changed|kegg}} | KEGG = D10530 }} |Section2={{Chembox Properties | Na=2 | Se=1 | O=3 | Appearance = colorless solid | Density = 3.1 g/cm<sup>3</sup> | MeltingPt = decomposes at 710 °C | BoilingPt = | Solubility = 85 g/100 mL (20 °C) | SolubleOther = insoluble in [[alcohol]], [[ethanol]] }} |Section3={{Chembox Structure | CrystalStruct = tetragonal }} |Section6={{Chembox Pharmacology | ATCCode_prefix = A12 | ATCCode_suffix = CE02 }} |Section7={{Chembox Hazards | ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics0698.htm ICSC 0698] | EUClass = Very toxic ('''T+''')<br/>Dangerous for the environment ('''N''') | RPhrases = {{R23}}, {{R28}}, {{R31}}, {{R43}}, {{R51/53}} | SPhrases = {{S1/2}}, {{S28}}, {{S36/37}}, {{S45}}, {{S61}} | NFPA-H = 3 | NFPA-F = 0 | NFPA-R = 0 | FlashPt = }} |Section8={{Chembox Related | OtherCompounds = [[Sodium sulfite]] <br> [[Sodium selenate]] <br> [[Sodium selenide]] }} }} '''Sodium selenite''' is a [[chemical compound]]. Its [[chemical formula]] is Na<sub>2</sub>SeO<sub>3</sub>. It contains [[sodium]]