Beryllium carbide

Beryllium carbide
Names
IUPAC name Beryllium carbide
Identifiers
CAS Number	506-66-1^Y
3D model (JSmol)	Interactive image
ChemSpider	61480^Y
ECHA InfoCard	100.007.319
EC Number	208-050-7
PubChem CID	68173
UNII	F5D2F26ONX^Y
CompTox Dashboard (EPA)	DTXSID6060137
InChI InChI=1S/C.2Be^Y Key: UQVOJETYKFAIRZ-UHFFFAOYSA-N^Y
SMILES [Be]=C=[Be]
Properties
Chemical formula	CBe₂
Molar mass	30.035 g·mol⁻¹
Appearance	Yellow to red crystals
Odor	odorless
Density	1.90 g cm⁻³ (at 15 °C)
Melting point	2,100 °C (3,810 °F; 2,370 K) (decomposes)
Solubility in water	decomposes
Structure
Crystal structure	cubic
Related compounds
Related compounds	Carbon dioxide Carbon diselenide Carbon disulfide
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]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is ^YN ?) Infobox references

Chemical compound

Beryllium carbide, or Be₂C, is a metal carbide.^[2] Similar to diamond, it is a very hard compound. It is used in nuclear reactors as a core material.

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:

2BeO + 3C → Be₂C + 2CO

Beryllium carbide decomposes very slowly in water and forms methane gas:

Be₂C + 2H₂O → 2BeO + 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 + 4OH⁻ → 2 BeO₂²⁻ + CH₄

References

^ ^a ^b ^c NIOSH Pocket Guide to Chemical Hazards. "#0054". National Institute for Occupational Safety and Health (NIOSH).
^ "Beryllium Carbide". American Elements. Retrieved 25 June 2023.