What is Hydrogen selenide?
{{about|the acidic gas|hydrogen selenide with one hydrogen taken away|hydroselenide}} {{chembox | Verifiedfields = changed | verifiedrevid = 477313484 | Name = Hydrogen selenide | ImageFileL1 = Hydrogen-selenide-2D-dimensions.svg | ImageNameL1 = Structural diagram of the hydrogen selenide molecule | ImageFileR1 = Hydrogen-selenide-3D-vdW.svg | ImageNameR1 = Space-filling model of the hydrogen selenide molecule | IUPACName = Hydrogen selenide | OtherNames = Hydroselenic acid<br />selane<br />selenium hydride |Section1={{Chembox Identifiers | PubChem = 533 | KEGG_Ref = {{keggcite|correct|kegg}} | KEGG = C01528 | InChI = 1/H2Se/h1H2 | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 16503 | SMILES = [SeH2] | InChIKey = SPVXKVOXSXTJOY-UHFFFAOYAF | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/H2Se/h1H2 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = SPVXKVOXSXTJOY-UHFFFAOYSA-N | CASNo = 7783-07-5 | CASNo_Ref = {{cascite|correct|CAS}} | UNII_Ref = {{fdacite|changed|FDA}} | UNII = V91P54KPAM | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 518 | RTECS = X1050000 | UNNumber = 2202 }} |Section2={{Chembox Properties | Formula = H<sub>2</sub>Se | MolarMass = 80.98 g/mol | Appearance = Colorless gas | Odor = decayed [[horseradish]]<ref name=PGCH>{{PGCH|0336}}</ref> | Density = 3.553 g/dm<sup>3</sup> | Solubility = 0.70 g/100 mL | SolubleOther = soluble in [[carbon disulfide|CS<sub>2</sub>]], [[phosgene]] | MeltingPtC = -65.73 | BoilingPtC = -41.25 | ConjugateAcid = Selenonium | ConjugateBase = [[Selenide]] | pKa = 3.89 | VaporPressure = 9.5 atm (21°C)<ref name=PGCH/> }} |Section3={{Chembox Structure | MolShape = Bent | Dipole = }} |Section7={{Chembox Hazards | MainHazards = Extremely toxic and flammable | ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics0284.htm ICSC 0284] | EUClass = {{Hazchem F+}} {{Hazchem T+}} {{Hazchem N}} | RPhrases = {{R23/25}}, {{R33}}, {{R50/53}} | SPhrases = {{S1/2}}, {{S20/21}}, {{S28}}, {{S45}}, {{S60}}, {{S61