barium peroxide

{{chembox

| Watchedfields = changed

| verifiedrevid = 443750435

| ImageFile = Peroxid barnatý.JPG

| ImageFile2 = BaO2structure.jpg

| ImageCaption2 = {{legend|lime|Barium cations {{chem2|Ba(2+)}}}}{{legend|red|Peroxide anions {{chem2|O2(2−)}}}}

| IUPACName = barium peroxide

| OtherNames = Barium binoxide,
Barium dioxide

|Section1={{Chembox Identifiers

| InChI = 1/Ba.O2/c;1-2/q+2;-2

| SMILES = [Ba+2].[O-][O-]

| InChIKey = ZJRXSAYFZMGQFP-UHFFFAOYAZ

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/Ba.O2/c;1-2/q+2;-2

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = ZJRXSAYFZMGQFP-UHFFFAOYSA-N

| CASNo = 1304-29-6

| CASNo_Ref = {{cascite|correct|CAS}}

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = T892KY013Y

| EINECS = 215-128-4

| PubChem = 14773

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID=14090

| RTECS = CR0175000

| UNNumber = 1449

}}

|Section2={{Chembox Properties

| Formula = {{chem2|BaO2}}

| MolarMass = 169.33 g/mol (anhydrous)
313.45 g/mol (octahydrate)

| Appearance = Grey-white crystalline solid (anhydrous)
Colorless solid (octahydrate)

| Odor = Odorless

| Density = 5.68 g/cm³ (anhydrous)
2.292 g/cm³ (octahydrate)

| MeltingPtC = 450

| BoilingPtC = 800

| BoilingPt_notes = (decomposes to BaO & oxygen.Accommodation of Excess Oxygen in Group II Monoxides - S.C. Middleburgh, R.W. Grimes and K.P.D. Lagerlof Journal of the American Ceramic Society 2013, Volume 96, pages 308–311. {{doi|10.1111/j.1551-2916.2012.05452.x}})

| Solubility = 0.091 g/(100 mL) (20 °C) (anhydrous)
0.168 g/cm³ (octahydrate)

| SolubleOther = dissolves with decomposition in acid

| MagSus = −40.6·10⁻⁶ cm³/mol

}}

|Section3={{Chembox Structure

| CrystalStruct = Tetragonal{{cite journal |last1=Massalimov |first1=I. A. |last2=Kireeva |first2=M. S. |last3=Sangalov |first3=Yu. A. |title=Structure and Properties of Mechanically Activated Barium Peroxide |year=2002 |journal=Inorganic Materials |volume=38 |issue=4 |pages=363–366 |doi=10.1023/A:1015105922260}}

| SpaceGroup = D¹⁷_4h, I4/mmm, tI6

| Coordination = 6

}}

|Section7={{Chembox Hazards

| GHSPictograms = {{GHS03}}{{GHS07}}

| GHSSignalWord = Warning

| HPhrases = {{H-phrases|272|302|332}}

| PPhrases = {{P-phrases|210|220|221|261|264|270|271|280|301+312|304+312|304+340|312|330|370+378|501}}

| NFPA-H = 3

| NFPA-F = 0

| NFPA-R = 2

| NFPA-S = ox

| FlashPt =

| AutoignitionPt =

}}

}}

Barium peroxide is an inorganic compound with the formula {{chem2|BaO2|auto=1}}. 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.