Barium carbide
Chemical compound
From Wikipedia, the free encyclopedia
Barium carbide (also referred to as barium ethynediide or barium acetylide)[1] is a chemical compound in the carbide family having the chemical formula BaC2.[2] It consists of barium cations Ba2+ and acetylide anions −C≡C−.
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| Names | |
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| IUPAC name
Barium ethynediide | |
| Other names
Barium acetylide | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| EC Number |
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| Properties | |
| BaC2 | |
| Molar mass | 161.349 g·mol−1 |
| Appearance | black crystalline solid |
| Density | 3.75 g/cm3 |
| Related compounds | |
Other cations |
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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
Barium carbide (BaC2) can be synthesized by several high-temperature reduction methods. An impure form of the compound is obtained by reducing powdered barium carbonate with metallic magnesium in the presence of carbon.[3]
Another laboratory-scale method involves the direct reduction of carbon dioxide with heated metallic barium at approximately 600 °C, producing barium carbide as an intermediate in studies of acetylene formation.[4]
Barium carbide may also be prepared by heating a mixture of a barium amalgam and powdered carbon under a stream of hydrogen, which facilitates the removal of mercury and promotes carbide formation.
The pure compound is typically obtained by carbothermal reduction of barium oxide with carbon at elevated temperatures, a method analogous to the industrial preparation of other alkaline earth metal carbides.[5]
Properties
Barium carbide reacts similarly to calcium carbide,[6] but it's more fusible. When exposed to extreme heat, the barium will evaporate leaving behind crystals of graphite. It can also absorb the carbon in a solution at high temperature.[7]