Barium peroxide
Tetragonal
Bariumsuperoxid
Colorless solid
Fixed
- 4.96 g · cm -3
- 2.29 g · cm -3
450 ° C.
Decomposition at 800 ° C.
- Low in water ( decomposition)
- Insoluble in ethanol and diethyl ether
Risk
0.5 g · m -3 ( barium)
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Barium peroxide is a chemical compound of the elements barium, and oxygen with the chemical formula BaO2. When heated above 700 ° C BaO2 releases oxygen. Barium peroxide may act, due to its relationship to the H2O2 as an oxidizing or as a reducing agent.
History
Barium peroxide is the first by Alexander von Humboldt ( 1799) has become known peroxo compound.
Production
Barium peroxide is produced by barium oxide is heated at about 500 ° C under elevated pressure with air. In the laboratory, it can also be obtained from barium chloride and hydrogen peroxide under basic conditions. This initially results in the octahydrate, which can then be converted, by heating in barium.
Properties
Barium peroxide is a very reactive oxidising white to gray solid, which decomposes in water. It decomposes above a temperature of 700 ° C, with oxygen and barium oxide is formed. Barium has a tetragonal crystal structure with space group I4/mmm, while the octahydrate also but has a tetragonal crystal structure with space group P4/mcc.
Use
Barium peroxide is mainly used in pyrotechnics supply oxygen and to produce green flame colorations. With magnesium powder is found in Zündkirschen application. Also, it is used for bleaching of lead glass and in the bleaching of straw, and silk.
Previously barium played for the industrial production of hydrogen peroxide (known as Brin cal peroxide process ) a major role:
Explanation:
Nowadays this procedure is almost completely ousted from the energetically less costly anthraquinone process.
Another historical process in which barium was used as an intermediate, was the Brinsche oxygen process for the industrial preparation of oxygen. In the first step of barium oxide BaO by heating with air that had been freed from CO2, barium peroxide produced, this step is the same as the second of the above peroxide Process:
After the air nitrogen was removed, then the barium was either heated further until it again gave the oxygen at 800 ° C, or oxygen was removed at 700 ° C with a vacuum pump:
The oxygen thus obtained was about 96% Like all chemical processes, which are used exclusively for the production of oxygen, it has no meaning, since the Linde process has prevailed.
Safety
When mixing barium peroxide with combustible material may cause an explosion.