Carbide
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Carbide is a polyatomic ion consisting of two carbon atoms or any salt containing such an ion. The ion carries a −2 charge.
Examples
- sodium carbide (Na2C2)
- silicon carbide (SiC)
- Tungsten carbide (often called simply carbide)
See Category:Carbides for a bigger list.
Properties
Under conditions of standard temperature and pressure, metal carbides react strongly with water to form metal oxides or hydroxides and flammable acetylene gas, e.g:
CaC2 + 2H2O → C2H2 + Ca(OH)2
Carbide lamps, an important source of portable subterranean illumination for mining and caving, and in the past for lighthouse lamps, work through on-demand production and combustion of acetylene by the metered addition of water to calcium carbide.
Gas lighting, using acetylene gas generated from carbide, was used in some homes before the incandescent lamp came into widespread use. It was also the main source of lighting on bicycles and carriages before the widespread availability of electric lamps and batteries.
External links
- See this page (http://www.americanscientist.org/template/AssetDetail/assetid/14761) for a good discussion on Carbide structures.
- See this page (http://arcmelt.velp.info/) how to make Calcium Carbide using an arc welder.de:Carbid
eo:Karbido fr:Carbide ja:カーバイド nl:Calciumcarbide pt:Carbeto sl:Karbid