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Barium peroxide

Barium peroxide
Peroxid barnatý.JPG
BaO2structure.jpg
Names
IUPAC name
barium peroxide
Other names
Barium binoxide,
Barium dioxide
Identifiers
1304-29-6 YesY
3D model (Jmol) Interactive image
ChemSpider 14090 YesY
ECHA InfoCard 100.013.754
EC Number 215-128-4
PubChem 14773
RTECS number CR0175000
Properties
BaO2
Molar mass 169.33 g/mol (anhydrous)
313.45 (octahydrate)
Appearance Grey-white crystalline (anhydrous)
colorless solid (octahydrate)
Odor odorless
Density 5.68 g/cm3 (anhydrous) 2.292 g/cm3 (octahydrate)
Melting point 450 °C (842 °F; 723 K)
Boiling point 800 °C (1,470 °F; 1,070 K) (decomposes to BaO & O2.)
anhydrous
0.091 g/100 mL (20 °C)
octahydrate
0.168 g/cm3
Solubility dissolves with decomposition in acid
-40.6·10−6 cm3/mol
Structure
Tetragonal
D174h, I4/mmm, tI6
6
Hazards
Oxidizing Agent O
Harmful Xn
R-phrases R8, R20/22
S-phrases (S2), S13, S27
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g., phosphorus Special hazard OX: Oxidizer. E.g., potassium perchlorateNFPA 704 four-colored diamond
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY  (what is YesYN ?)
Infobox references

Barium peroxide is the inorganic compound with the formula BaO2. This white solid (gray when impure) is one of the most common inorganic peroxides, and it was the first peroxide compound discovered. Being an oxidizer and giving a vivid green colour upon ignition (as do all barium compounds), it finds some use in fireworks; historically, it was also used as a precursor for hydrogen peroxide.

Barium peroxide is a peroxide, containing O2−
2 subunits. The solid is isomorphous to calcium carbide, CaC2.

Barium peroxide arises by the reversible reaction of O2 with barium oxide. The peroxide forms around 500 °C and oxygen is released above 820 °C.

This reaction is the basis for the now-obsolete Brin process for separating oxygen from the atmosphere. Other oxides, e.g. Na2O and SrO, behave similarly.

In another obsolete application, barium peroxide was once used to produce hydrogen peroxide via its reaction with sulfuric acid:

The insoluble barium sulfate is filtered from the mixture.


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