Beryllium carbide

Beryllium carbide, or Be2C, is a metal carbide. 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