Sodium selenide
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| Names | |
|---|---|
| IUPAC name
sodium selenide | |
| Identifiers | |
1313-85-5  | |
| 3D model (Jmol) | Interactive image |
| ChEBI | CHEBI:77773  |
| ECHA InfoCard | 100.013.830 |
| EC Number | 215-212-0 |
| PubChem | 73973 |
| |
| |
| 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 |
| Related compounds | |
| Other anions |
Sodium sulfide Sodium telluride Sodium oxide |
| Other cations |
Hydrogen selenide Antimony selenide Aluminum selenide |
| Related compounds |
Sodium selenite Sodium selenate |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| verify (what is ?) | |
| Infobox references | |
Sodium selenide is an inorganic compound of sodium and selenium with the chemical formula Na2Se.
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
- ↑ David R. Lide (ed.). CRC Handbook of Chemistry and Physics (90th ed.). ISBN 978-1-4200-9084-0.
- ↑ Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 421.