Calcium peroxide

{{Short description|Chemical compound}}

{{Redirect|CaO2|"CaO2" as a symbol for arterial oxygen content|Hypoxia (medical)#arterial oxygen content}}

{{Chembox

| Watchedfields = changed

| verifiedrevid = 476998612

| Name = Calcium peroxide

| ImageFile = Crystal structure of CaO2.jpg

| ImageName = Calcium peroxide

| OtherNames = {{Unbulleted list

| Calcium dioxide{{cite web | url=https://sor.epa.gov/sor_internet/registry/substreg/searchandretrieve/advancedsearch/externalSearch.do?p_type=SRSITN&p_value=82271 | title=Substance Registry Services | US EPA }}

}}

|Section1={{Chembox Identifiers

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

| ChemSpiderID = 14096

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

| UNII = 7FRO2ENO91

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

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 48233

| EC_number = 215-139-4

| Gmelin = 674257

| KEGG = C18566

| UNNumber = 1457

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

| InChIKey = LHJQIRIGXXHNLA-UHFFFAOYAW

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

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

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

| StdInChIKey = LHJQIRIGXXHNLA-UHFFFAOYSA-N

| CASNo = 1305-79-9

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

| PubChem = 14779

| RTECS = EW3865000

}}

|Section2={{Chembox Properties

| Ca=1 | O=2

| Density = 2.91 g/cm³

| Appearance = white or yellowish powder

| Odor = odorless

| Solubility = decomposes

| MeltingPt= ~

| MeltingPtC = 355

| MeltingPt_notes = (decomposes)

| BoilingPt =

| pKa = 12.5

| RefractIndex = 1.895

| MagSus = −23.8·10⁻⁶ cm³/mol

}}

|Section3={{Chembox Structure

| CrystalStruct = Orthorhombic{{cite journal |journal=RSC Advances |year=2013 |title=Structures and stabilities of alkaline earth metal peroxides XO2 (X = Ca, Be, Mg) studied by a genetic algorithm |first1=X. |last1=Zhao |doi=10.1039/C3RA43617A |last2=Nguyen |first2=M.C. |last3=Wang |first3=C.Z. |last4=Ho |first4=K.M. |volume=3 |issue=44 |page=22135 |bibcode=2013RSCAd...322135Z |url=https://zenodo.org/record/1230026 }}

| SpaceGroup = Pna2₁

| Coordination = 8

}}

|Section7={{Chembox Hazards

| ExternalSDS =

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

| GHSSignalWord = Warning

| HPhrases = {{H-phrases|272|315|319|335}}

| PPhrases = {{P-phrases|210|220|221|261|264|271|280|302+352|304+340|305+351+338|312|321|332+313|337+313|362|370+378|403+233|405|501}}

| LD50 = >5000 mg/kg (oral, rat)
>10000 mg/kg (dermal, rat)

}}

|Section8={{Chembox Related

| OtherAnions = Calcium oxide

| OtherCations = Strontium peroxide
Barium peroxide
Sodium peroxide

}}

}}

Calcium peroxide or calcium dioxide is the inorganic compound with the formula CaO₂. It is the peroxide (O₂²⁻) salt of Ca²⁺. Commercial samples can be yellowish, but the pure compound is white. It is almost insoluble in water.{{Ullmann | title = Peroxo Compounds, Inorganic | vauthors = Jakob H, Leininger S, Lehmann T, Jacobi S, Gutewort S |display-authors=3| doi = 10.1002/14356007.a19_177.pub2}}