Beryllium carbide
| Names | |
|---|---|
| IUPAC name
Beryllium carbide | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.007.319 |
| EC Number | 208-050-7 |
PubChem CID |
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| Properties | |
| CBe2 | |
| Molar mass | 30.04 g·mol−1 |
| Appearance | Yellow crystals |
| Odor | odorless |
| Density | 1.90 g cm−3 (at 15 °C) |
| Melting point | 2,100 °C (3,810 °F; 2,370 K) (decomposes) |
| decomposes | |
| Hazards | |
| US health exposure limits (NIOSH): | |
PEL (Permissible) |
TWA 0.002 mg/m3 C 0.005 mg/m3 (30 minutes), with a maximum peak of 0.025 mg/m3 (as Be)[1] |
REL (Recommended) |
Ca C 0.0005 mg/m3 (as Be)[1] |
IDLH (Immediate danger) |
Ca [4 mg/m3 (as Be)][1] |
| Related compounds | |
Related compounds |
Carbon dioxide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
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| Infobox references | |
Beryllium carbide, or Be2C, is a metal carbide. Similar to diamond, it is a very hard compound.[2]
Preparation
Beryllium carbide is prepared by heating the elements beryllium and carbon at elevated temperatures (above 900°C). It also may be prepared by reduction of beryllium oxide with carbon at a temperature above 1,500°C:
- 2BeO + 3C → Be2C + 2CO
Beryllium carbide decomposes very slowly in water:
- Be2C + 2H2O → 2BeO + CH4
The rate of decomposition is faster in mineral acids with evolution of methane.
- Be2C + 4 H+ → 2 Be2+ + CH4
However, in hot concentrated alkali the reaction is very rapid, forming alkali metal beryllates and methane:
- Be2C + 4OH− → 2 BeO22− + CH4
See also
References
- 1 2 3 "NIOSH Pocket Guide to Chemical Hazards #0054". National Institute for Occupational Safety and Health (NIOSH).
- ↑ Beryllium Carbide Info American Elements Retrieved June 11, 2009.
External links
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