Sodium peroxide 2010836 222086764 2008-06-27T14:21:39Z Kirikou fr 5168652 {{Chembox new | Name = Sodium peroxide | ImageFile = Sodium-peroxide-unit-cell-3D-balls.png <!-- | ImageSize = 150px --> | ImageName = Sodium peroxide | ImageFile1 = Sodium-peroxide-3D-vdW.png <!-- | ImageSize1 = 150px --> | ImageFile2 = Sodiumperoxide.JPG <!-- | ImageSize2 = 150px --> | OtherNames = Sodium dioxide, Natrium peroxide,<br /> Flocool, Solozone, Disodium peroxide | Section1 = {{Chembox Identifiers | CASNo = 1313-60-6 }} | Section2 = {{Chembox Properties | Formula = Na<sub>2</sub>O<sub>2</sub> | MolarMass = 78 g/mol | Density = 2.8 g/cm<sup>3</sup> | Solvent = other solvents | SolubleOther = reacts with water | MeltingPt = 675 °C | Appearance = yellow to white powder }} | Section3 = {{Chembox Structure | CrystalStruct = hexagonal<ref name="Tallman">Tallman, R. L.; Margrave, J. L.; Bailey, S. W. ''J. Am. Chem. Soc.'' '''1957''', ''79'', 2979-80.</ref> }} | Section4 = {{Chembox Thermochemistry | DeltaHf = -513 kJ mol-1 <!--ΔG °f = -449 kJ mol-1--> <ref name="dic">Macintyre, J. E., ed. ''Dictionary of Inorganic Compounds,'' Chapman & Hall: 1992.</ref> | DeltaHc = | Entropy = 95 J K-1 mol-1<ref name="dic"/> | HeatCapacity = }} | Section7 = {{Chembox Hazards | ExternalMSDS = [http://www.jtbaker.com/msds/englishhtml/s4710.htm External MSDS] | MainHazards = Strong oxidizer, reacts with water | NFPA-H = 3 | NFPA-R = 1 | Other=OX | NFPA-F = 0 | RPhrases = {{R7}}, {{R14}}, {{R26/27/28}}, {{R29}}, {{R41}} | SPhrases = {{S7/8}}, {{S37/39}} }} | Section8 = {{Chembox Other | OtherCations = [[hydrogen peroxide]], [[lithium peroxide]],<br /> [[calcium peroxide]] | Related [[oxide]]s | [[sodium oxide]], [[sodium superoxide]]}} }} '''Sodium peroxide''', Na<sub>2</sub>O<sub>2</sub>, is the normal product when sodium is burned. It is a strong oxidizer. ==Chemical Properties== Sodium peroxide is [[hydrolysis|hydrolyzed]] by water to form [[sodium hydroxide]] plus [[hydrogen peroxide]] according to the reaction: : Na<sub>2</sub>O<sub>2</sub> + 2 H<sub>2</sub>O &rarr; 2 NaOH + H<sub>2</sub>O<sub>2</sub> The hydrogen peroxide thus formed decomposes rapidly in the ensuing basic solution, producing water and oxygen. The reaction is substantially exothermic and can set fire to combustible materials. Sodium peroxide will also set fire to many organic liquids on contact (particularly [[alcohol]]s and [[glycol]]s), and reacts violently with powdered metals and numerous other compounds after minimal initiation. ==Structural Transitions== The hexagonal crystal structure of sodium peroxide was discovered by Tallman ''et al.''<ref name="Tallman"/>. Upon heating, the structure undergoes a transition into a phase of unknown symmetry at 512 °C.<ref name="dic"/> With further heating above the 675 °C melting point, the compound decomposes, releasing O<sub>2</sub>, before reaching a boiling point.<ref name="Lewis">Lewis, R. J. ''Sax's Dangerous Properties of Industrial Materials, 10th ed.'', John Wiley & Sons, Inc.: 2000.</ref> ==Preparation== Sodium peroxide can be synthesized by direct reaction with sodium and oxygen at 130 - 200 °C.<ref name="dic"/> Lower temperature (0 - 20 °C) synthesis can be achieved by passing O<sub>2</sub> over a dilute (0.1 - 5.0 mole percent) sodium metal [[amalgam]], thus oxidizing the sodium.<ref>Schechter, D. L.; Bon, C. K.; Leddy, J. J.; ''Process for the Preparation of Sodium Peroxide by the Oxidation of a Sodium Amalgam,'' U.S. Patent 3,141,736. Filed 7 May 1962.</ref> It may also be produced by passing ozone gas over solid [[sodium iodide]] inside a [[platinum]] or [[palladium]] tube. The ozone oxidizes the sodium to form sodium peroxide. The [[iodine]] is freed into iodine crystals, which can be sublimed by mild heating. The platinum or palladium catalyzes the reaction and is not attacked by the sodium peroxide. ==Uses== Given its strong oxidation properties, sodium peroxide is used to bleach wood pulp for the production of paper. It has also been used for the extraction of minerals from various ores. Sodium peroxide may go by the commercial names of ''Solozone''<ref name="dic"/> and ''Flocool.''<ref name="Lewis"/> In chemistry preparations, sodium peroxide is used as an oxidising agent. ==References== {{reflist}} [[Category:Peroxides]] [[Category:Sodium compounds]] [[ar:فوق أكسيد صوديوم]] [[bs:Natrijum peroksid]] [[cs:Peroxid sodný]] [[de:Natriumperoxid]] [[fr:peroxyde de sodium]] [[es:Peróxido de sodio]] [[ja:過酸化ナトリウム]] [[ru:Пероксид натрия]] [[zh:过氧化钠]]