Hydrogen telluride
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| Names | |||
|---|---|---|---|
| IUPAC name
hydrogen telluride
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| Other names
hydrotelluric acid
tellane tellurium hydride | |||
| Identifiers | |||
| ECHA InfoCard | 100.029.073 | ||
PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |||
| H2Te | |||
| Molar mass | 129.6158 g mol−1 | ||
| Appearance | colourless gas | ||
| Density | 3.310 g/cm3, gas 2.57 g/cm3 (-20 °C, liquid) | ||
| Melting point | −49 °C [1] | ||
| Boiling point | −2.2 °C (unstable above -2 °C) | ||
| 0.70 g/100 mL | |||
| Acidity (pKa) | 2.6 | ||
| Structure | |||
| bent | |||
| Thermochemistry | |||
Std enthalpy of
formation (ΔfH⦵298) |
0.7684 kJ/g | ||
| Hazards | |||
| Occupational safety and health (OHS/OSH): | |||
Main hazards
|
toxic | ||
| Related compounds | |||
Other anions
|
H2O H2S H2Se H2Po | ||
Other cations
|
Na2Te Ag2Te | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Hydrogen telluride is the inorganic compound with the formula H2Te. The simplest hydride of tellurium, it is rarely encountered because of its tendency to decompose to the constituent elements. Most compounds with Te-H bonds are unstable with respect to loss of H2. H2Te is chemically and structurally similar to hydrogen selenide, both are acidic species with H-X-H angles approaching 90°.[2] This compound has a very unpleasant smell of decayed leeks / garlic.[citation needed]
Synthesis
H2Te is prepared by the acidification of salts of Te2−, such as Al2Te3 and Na2Te.[3] Na2Te can be generated by the reaction of Na and Te in anhydrous ammonia. The intermediate in the acidification, HTe−
is a stable anion. Sodium hydrogen telluride, NaHTe, can be made by reducing tellurium with NaBH
4.[3]
Properties
H
2Te is an endothermic compound, unstable in air and easily oxidised to water and elemental tellurium:[4]
- 2 H
2Te + O
2 → 2 H
2O + 2 Te
It is almost as acidic as phosphoric acid (Ka = 8.1×10−3), having a Ka value of about 2.3×10−3.[4] It reacts with many metals to form tellurides.[5]
See also
References
- ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0070494398
- ^ Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth-Heinemann. ISBN 0-7506-3365-4.
- ^ a b Nicola Petragnani; Hélio A. Stefani (2007). Tellurium in organic synthesis. Best synthetic methods (2nd ed.). Academic Press. p. 6. ISBN 0080453104.
- ^ a b Egon Wiberg; Arnold Frederick Holleman (2001). Nils Wiberg (ed.). Inorganic chemistry. Academic Press. p. 589. ISBN 0123526515.
{{cite book}}: Unknown parameter|other=ignored (|others=suggested) (help) - ^ Henry Enfield Roscoe; Carl Schorlemmer (1878). A treatise on chemistry. Vol. 1. Appleton. pp. 367–368.