Aluminium selenide

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Aluminium selenide[1]
Aluminum selenide
Identifiers
CAS number 1302-82-5
PubChem 164804
ChemSpider 144477 YesY
EC number 215-110-6
Jmol-3D images Image 1
Properties
Molecular formula Al2Se3
Molar mass 290.84 g/mol
Appearance yellow to brown powder
Odor odorless
Density 3.437 g/cm3
Melting point 947 °C (1,737 °F; 1,220 K)
Solubility in water decomposes
Structure
Crystal structure Monoclinic, mS20, Space group Cc, No. 9[2]
Thermochemistry
Std molar
entropy
So298
154.8 J/mol K
Std enthalpy of
formation
ΔfHo298
-566.9 kJ/mol
Hazards
EU classification not listed
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g., fluorine Special hazards (white): no codeNFPA 704 four-colored diamond
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Aluminium selenide is the inorganic compound with the formula Al2Se3.

Preparation[edit]

It is a solid prepared by igniting a mixture of the elements at 1,000 °C (1,830 °F):

2 Al + 3 Se → Al2Se3

The pure compound is white, but typical samples are coloured.[3] Samples of aluminium selenide must be protected from moisture, because the compound hydrolyzes readily, giving off highly toxic hydrogen selenide gas:[4]

Al2Se3 + 3 H2O → Al2O3 + 3 H2Se

Uses[edit]

Al2Se3 has been used as a precursor to hydrogen selenide, which is released when the solid is treated with acids.[3]

Safety[edit]

Aluminium selenide should be stored and handled away from moisture and air.

References[edit]

  1. ^ Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, FL: CRC Press. pp. 4–40. ISBN 0-8493-0594-2 
  2. ^ Steigmann, G. A.; Goodyear, J. (1966). "The crystal structure of Al2Se3". Acta Crystallographica 20: 617. doi:10.1107/S0365110X66001506. 
  3. ^ a b G. R. Waitkins, R. Shutt "Aluminum Selenide and Hydrogen Selenide" Inorganic Syntheses, 1946, vol. 2, pp. 183–186. doi:10.1002/9780470132333.ch55
  4. ^ Bernd E. Langner "Selenium and Selenium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. doi:10.1002/14356007.a23_525.