Beryllium carbide

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Beryllium carbide
Names
IUPAC name
Beryllium carbide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.007.319
EC Number 208-050-7
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
NFPA 704
Flammability code 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g., gasoline) Health code 4: Very short exposure could cause death or major residual injury. E.g., VX gas Reactivity code 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g., phosphorus Special hazards (white): no codeNFPA 704 four-colored diamond
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

Carbon diselenide
Carbon disulfide

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[edit]

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[edit]

References[edit]

External links[edit]