{{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 438998048 | Name = Hydrogen telluride | ImageFile = Hydrogen telluride.png | ImageSize = 125 | ImageCaption = Liquid hydrogen telluride in a test tube | ImageFile1 = Hydrogen-telluride-2D-dimensions.svg | ImageName1 = Structural diagram of the hydrogen telluride molecule | ImageClass1 = skin-invert | ImageFile2 = Hydrogen-telluride-3D-vdW.svg | ImageName2 = Space-filling model of the hydrogen telluride molecule | ImageSize2 = 115 | ImageCaption2 = {{legend|rgb(256,128,0)|Tellurium, Te}}{{legend|white|Hydrogen, H}} | ImageClass2 = bg-transparent | IUPACName = hydrogen telluride | OtherNames = hydrotelluric acid<br />tellane<br />tellurium hydride<br />dihydrogen telluride | Section1 = {{Chembox Identifiers | CASNo_Ref = {{cascite|correct|??}} | CASNo = 7783-09-7 | UNII_Ref = {{fdacite|changed|FDA}} | UNII = 7F4735942K | PubChem = 21765 | EINECS = 236-813-4 | ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}} | ChemSpiderID = 20455 | SMILES = [TeH2] | StdInChI_Ref = {{stdinchicite|changed|chemspider}} | StdInChI = 1S/H2Te/h1H2 | StdInChIKey_Ref = {{stdinchicite|changed|chemspider}} | StdInChIKey = VTLHPSMQDDEFRU-UHFFFAOYSA-N | ChEBI_Ref = {{ebicite|changed|EBI}} | ChEBI = 30452 | RTECS = }} | Section2 = {{Chembox Properties | Formula = {{chem2|H2Te}} |H=2|Te=1 | Appearance = colourless gas | Odor = Pungent, resembles rotting garlic or leeks | Density = 3.310 g/L, gas <br> 2.57 g/cm<sup>3</sup> (−20 °C, liquid) | Solubility = 0.70 g/100 mL | MeltingPtC = −49 | MeltingPt_ref = <ref>{{RubberBible87th}}</ref> | BoilingPtC = −2.2 | BoilingPt_notes = (unstable above −2 °C) | ConjugateAcid = Telluronium | ConjugateBase = Telluride | pKa = 2.6 }} | Section4 = {{Chembox Thermochemistry | DeltaHf = 0.7684 kJ/g | DeltaHc = | Entropy = | HeatCapacity = }} | Section3 = {{Chembox Structure | MolShape = bent | Dipole = }} | Section7 = {{Chembox Hazards | ExternalSDS = | MainHazards = Highly toxic and flammable | FlashPt = | NFPA-H = 4 | NFPA-F = 4 | NFPA-R = 1 }} | Section8 = {{Chembox Related | OtherAnions = H<sub>2</sub>O<br />H<sub>2</sub>S<br />H<sub>2</sub>Se<br />H<sub>2</sub>Po | OtherCations =Li<sub>2</sub>Te<br /> Na<sub>2</sub>Te<br />Ag<sub>2</sub>Te<br />K<sub>2</sub>Te<br />Rb<sub>2</sub>Te<br />Cs<sub>2</sub>Te | OtherCompounds = Telluric acid <br> Tellurous acid <br> Stibine }} }}
'''Hydrogen telluride''' is the inorganic compound with the formula H<sub>2</sub>Te. A hydrogen chalcogenide and the simplest hydride of tellurium, it is a colorless gas. Although unstable in ambient air, the gas can exist long enough to be readily detected by its rotting garlic-like odour at extremely low concentrations, or by the revolting odour of rotting leeks that it has at somewhat higher concentrations. Most compounds with Te–H bonds (tellurols) are unstable with respect to loss of H<sub>2</sub>. H<sub>2</sub>Te is chemically and structurally similar to hydrogen selenide, and both are acidic. The H–Te–H angle is about 90°. Volatile tellurium compounds often have unpleasant odours, reminiscent of decayed leeks or garlic.<ref name=Greenwood>Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth-Heinemann. {{ISBN|0-7506-3365-4}}.</ref>
==Synthesis== Electrolytic methods have been developed.<ref name=Brauer>F. Fehér, "Hydrogen Telluride" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. pp. 438.</ref> H<sub>2</sub>Te can also be prepared by hydrolysis of the telluride derivatives of electropositive metals.<ref>Shriver, Atkins. Inorganic Chemistry, Fifth Edition. W. H. Freeman and Company, New York, 2010; pp 407.</ref> The typical hydrolysis is that of aluminium telluride:
:Al<sub>2</sub>Te<sub>3</sub> + 6 H<sub>2</sub>O → 2 Al(OH)<sub>3</sub> + 3 H<sub>2</sub>Te
Other salts of Te<sup>2−</sup> such as MgTe and sodium telluride can also be used. Na<sub>2</sub>Te can be made by the reaction of Na and Te in anhydrous ammonia.<ref name="petragnani">{{cite book | title = Tellurium in organic synthesis | series = Best synthetic methods | author1 = Nicola Petragnani | author2 = Hélio A. Stefani | edition = 2nd | publisher = Academic Press | year = 2007 | isbn = 978-0-08-045310-1 | page = 6 }}</ref> The intermediate in the hydrolysis, {{chem|HTe|-}}, can be isolated as salts as well. NaHTe can be made by reducing tellurium with {{chem|NaBH|4}}.<ref name="petragnani"/>
Hydrogen telluride cannot be efficiently prepared from its constituent elements, in contrast to H<sub>2</sub>Se.<ref name=Brauer/>
==Properties== {{chem|H|2|Te}} is an endothermic compound, degrading to the elements at room temperature: : {{chem|H|2|Te}} → {{chem|H|2}} + Te Light accelerates the decomposition. It is unstable in air, being oxidized to water and elemental tellurium:<ref name="wiberg2001">{{cite book | title = Inorganic chemistry | author = Egon Wiberg | author2 = Arnold Frederick Holleman | editor = Nils Wiberg | translator = Mary Eagleson | publisher = Academic Press | year = 2001 | isbn = 0-12-352651-5 | page = 589 }}</ref> :2 {{chem|H|2|Te}} + {{chem|O|2}} → 2 {{chem|H|2|O}} + 2 Te
It is almost as acidic as phosphoric acid (''K''<sub>a</sub> = {{Val|8.1e-3}}), having a ''K''<sub>a</sub> value of about {{Val|2.3e-3}}.<ref name="wiberg2001"/> It reacts with many metals to form tellurides.<ref>{{cite book | title = A treatise on chemistry | volume = 1 | author = Henry Enfield Roscoe | author2 = Carl Schorlemmer | publisher = Appleton | year = 1878 | pages = 367–368 }}</ref>
==See also== *Dimethyl telluride
==References== {{reflist}}
{{Hydrogen compounds}} {{Hydrides by group}} {{Tellurides}}
{{DEFAULTSORT:Hydrogen Telluride}} Category:Hydrogen compounds Category:Triatomic molecules Category:Tellurides Category:Foul-smelling chemicals