Beryllium carbide
Chemical compound
From Wikipedia, the free encyclopedia
Beryllium carbide is a chemical compound with the chemical formula Be2C. It is a metal carbide.[2] Similar to diamond, it is a very hard compound. It is used in nuclear reactors as a core material.
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| Names | |
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| IUPAC name
Beryllium carbide | |
| Other names
Beryllium methanide | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.007.319 |
| EC Number |
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PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| Be2C | |
| Molar mass | 30.035 g·mol−1 |
| Appearance | Yellow to red crystals |
| Odor | odorless |
| Density | 1.90 g/cm3 (at 15 °C) |
| Melting point | 2,100 °C (3,810 °F; 2,370 K) (decomposes) |
| decomposes | |
| Structure | |
| cubic | |
| Hazards | |
| NIOSH (US health exposure limits): | |
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 |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Preparation
Beryllium carbide is prepared by heating the elements beryllium and carbon at elevated temperatures (above 950°C). It also may be prepared by reduction of beryllium oxide with carbon at a temperature above 1,500°C:
- 2 BeO + 3 C → Be2C + 2 CO
Beryllium carbide decomposes very slowly in water and forms methane gas:
- Be2C + 2 H2O → 2 BeO + CH4
The rate of decomposition is faster in mineral acids with evolution of methane.
- Be2C + 4 H+ → 2 Be2+ + CH4
In hot concentrated alkali the reaction is very rapid, forming alkali metal beryllates and methane:
- Be2C + 4 OH− → 2 BeO2−2 + CH4
