Sodium selenide
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Names | |
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IUPAC name
sodium selenide
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Identifiers | |
1313-85-5 | |
ChEBI | CHEBI:77773 |
EC Number | 215-212-0 |
Jmol 3D model | Interactive image |
PubChem | 73973 |
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Properties | |
Na2Se | |
Molar mass | 124.95 g·mol−1 |
Appearance | white to red solid |
Odor | unpleaseant |
Density | 2.625 g cm−3[1] |
Melting point | 875 °C (1,607 °F; 1,148 K) |
reacts with water | |
Structure | |
cubic | |
Thermochemistry | |
Std molar
entropy (S |
105 J/mol K |
Std enthalpy of
formation (ΔfH |
-343 kJ/mol |
Vapor pressure | {{{value}}} |
Related compounds | |
Other anions
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Sodium sulfide Sodium telluride Sodium oxide |
Other cations
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Hydrogen selenide Antimony selenide Aluminum selenide |
Related compounds
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Sodium selenite Sodium selenate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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verify (what is ?) | |
Infobox references | |
Sodium selenide is an inorganic compound of sodium and selenium with the chemical formula Na2Se.
Contents
Preparation
This colourless solid is prepared by the reaction of selenium with a solution of sodium in liquid ammonia at -40 °C.[2]
Alternatively, sodium selenide can be prepared by the reaction of gaseous hydrogen selenide with metallic sodium at 100 °C.
Reactions
Like other alkali metal chalcogenides, this material is highly sensitive to water, easily undergoing hydrolysis to give mixtures of sodium biselenide (NaSeH) and hydroxide. This hydrolysis occurs because of the extreme basicity of the Se2− ion.
- Na2Se + H2O → NaHSe + NaOH
Similarly, sodium selenide is readily oxidized to polyselenides, a conversion signaled by off-white samples.
Sodium selenide reacts with acids to produce toxic hydrogen selenide gas.
- Na2Se + 2 HCl → H2Se + 2 NaCl
The compound reacts with electrophiles to produce the selenium compounds. With alkyl halides, one obtains a variety of organoselenium compounds:
- Na2Se + 2 RBr → R2Se + 2 NaBr
Organotin and organosilicon halides react similarly to give the expected derivatives:
- Na2Se + 2 Me3XCl → (Me3X)2Se + 2 NaCl (X ∈ Si, Ge, Sn)
Safety
Sodium selenide should be stored and handled away from moisture and air.
References
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