Magnesium oxide 162269 225597852 2008-07-14T14:08:59Z Fulcanelli 7422369 [[pt:Óxido de magnésio]] <!--This article is in Commonwealth English--> {{chembox new | ImageFile = Magnesium oxide.jpg | ImageSize = | IUPACName = Magnesium oxide | SystematicName = | OtherNames = Magnesia | Section1 = {{Chembox Identifiers | Abbreviations = | CASNo = | EINECS = | EINECSCASNO = | PubChem = | SMILES = | InChI = | RTECS = | MeSHName = | ChEBI = | KEGG = | ATCCode_prefix = | ATCCode_suffix = | ATC_Supplemental =}} | Section2 = {{Chembox Properties | Formula = MgO | MolarMass = 40.3044 g/mol | Appearance = white powder | Density = 3.58 g/cm<sup>3</sup> | MeltingPt = 3073 K (2800 C) | Melting_notes = | BoilingPt = 3873 K (3600 C) | Boiling_notes = | Solubility = 0.0086 g / 100 mL<ref>https://fscimage.fishersci.com/msds/13450.htm</ref> | SolubleOther = | Solvent = | LogP = | VaporPressure = | HenryConstant = | AtmosphericOHRateConstant = | pKa = | pKb = }} | Section3 = {{Chembox Structure | CrystalStruct = [[cubic crystal system|Cubic]], [[Pearson symbol|cF8]] | SpaceGroup = Fm<u style="text-decoration:overline">3</u>m, #225 | Coordination = Mg,octahedral<br /> O,octahedral | LattConst_a = | LattConst_b = | LattConst_c = | LattConst_alpha = | LattConst_beta = | LattConst_gamma = | MolShape = | OrbitalHybridisation = | Dipole = }} | Section4 = {{Chembox Thermochemistry | DeltaHf = | DeltaHc = | Entropy = | HeatCapacity = }} | Section5 = {{Chembox Pharmacology | AdminRoutes = | Bioavail = | Metabolism = | HalfLife = | ProteinBound = | Excretion = | Legal_status = | Legal_US = | Legal_UK = | Legal_AU = | Legal_CA = | PregCat = | PregCat_AU = | PregCat_US = }} | Section6 = {{Chembox Explosive | ShockSens = | FrictionSens = | ExplosiveV = | REFactor = }} | Section7 = {{Chembox Hazards | EUClass = | EUIndex = | MainHazards = Metal fume fever; May cause irritation in eyes or respiratory tract | NFPA-H = 1 | NFPA-F = 0 | NFPA-R = 0 | NFPA-O = | RPhrases = | SPhrases = | RSPhrases = | FlashPt = | Autoignition = | ExploLimits = | LD50 = | PEL = }} | Section8 = {{Chembox Related | OtherAnions = | OtherCations = | OtherFunctn = | Function = | OtherCpds = }} }} '''Magnesium oxide''', or '''magnesia''', is a white solid [[mineral]] that occurs naturally as [[periclase]] and is a source of [[magnesium]] (see also [[oxide]]). It has an [[empirical formula]] of {{Magnesium}}{{Oxygen}}. It is formed by an [[ionic bond]] between one magnesium and one oxygen [[atom]]. Magnesium oxide is easily made by burning magnesium ribbon which oxidizes in a bright [[white]] [[light]], resulting in a [[Powder (substance)|powder]]. It is [[hygroscopic]] in nature and care must be taken to protect it from moisture. [[Magnesium hydroxide]] forms in the presence of water (MgO + H<sub>2</sub>O → Mg(OH)<sub>2</sub>), but it can be reversed by heating it to separate moisture. The crystal structure of MgO matches the crystal structure of [[Sodium chloride|NaCl]].<ref>[http://www.webelements.com/webelements/compounds/text/Mg/Mg1O1-1309484.html Chemistry : Periodic Table : magnesium : compound data [magnesium (II) oxide&#93;<!-- Bot generated title -->]</ref> ==Applications== * In medicine, magnesium oxide is used for relief for heartburn and sore stomach, as an antacid, magnesium supplement, and as a short-term [[laxative]]. It is also used to improve symptoms of [[indigestion]]. Side effects of magnesium oxide may include nausea and cramping.<ref>[http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a601074.html MedlinePlus] medicinal use</ref> * It is used by many libraries for preserving books by reacting with ambient moisture to dry the book storage areas. * It is used as an insulator in [[Mineral-insulated copper-clad cable|industrial cables]]. * It is used as a basic [[refractory]] material for lining [[crucible]]s. * It is used as a principal ingredient in construction materials used for fireproofing. * It is used as a reference white color in [[colorimetry]], owing to its good [[diffuser (optics)|diffusing]] and [[reflectivity]] properties.<ref>{{cite journal|title=Reflectance of Magnesium Oxide|first=Peter A.|last=Tellex|coauthors=Waldron, Jack R.|journal=[[JOSA]]|month=January|year=1955|volume=45|number=1| url=http://www.opticsinfobase.org/abstract.cfm?URI=josa-45-1-19}}</ref> It may be smoked onto the surface of an opaque material to form an [[integrating sphere]]. * It is used as an insulator in devices that exhibit the [[tunnel magnetoresistance]] effect. * It is used extensively in electrical heating as a component of "CalRod"-styled [[heating element]]s. There are several mesh sizes available and most commonly used ones are 40 and 80 mesh per the [[American Foundry Society]]. The extensive use is due to its high dielectric strength and average thermal conductivity. MgO is usually crushed and compacted with minimal airgaps or voids. The electrical heating industry also experimented with [[aluminium oxide]], but it is not used anymore. * It is used in feeding animals and there are special grades available. * An industrial use of magnesium oxide is in leather processing, as a basifying agent on chrome tanning process.{{Clarifyme|date=March 2008}} * Pressed MgO is used as an optical material. It is transparent from 300 nm to 7 µm. The [[refractive index]] is 1.72 at 1 µm and the [[Abbe number]] is 53.58. It is sometimes known by the [[Eastman Kodak]] trademarked name '''Irtran-5''', although this designation is long since obsolete. Crystalline pure MgO is available commercially and has small use in infrared optics.<ref>[http://nvl.nist.gov/pub/nistpubs/jres/049/4/V49.N04.A03.pdf Index of Refraction of Magnesium Oxide] Robert E. Stephens and Irving H. Malitson</ref> ==Precautions== Inhalation of magnesium oxide fumes can cause [[metal fume fever]].<ref>[http://www.npi.gov.au/database/substance-info/profiles/51.html National Pollutant Inventory - Magnesium Oxide Fume Fact Sheet]</ref> ==See also== * [[Calcium oxide]] * [[Barium oxide]] * [[Magnesium sulfide]] ==References== <references /> ==External links== * [http://www.cmmp.ucl.ac.uk/~ahh/research/crystal/mgo.htm Data page at UCL] * [http://www.ceramics.nist.gov/srd/summary/ftgmgo.htm Ceramic data page at NIST] [[Category:Magnesium minerals]] [[Category:Magnesium compounds]] [[Category:Oxides]] [[Category:Refractory materials]] [[Category:Optical materials]] [[Category:Ceramic materials]] [[ca:Òxid de magnesi]] [[da:Magnesiumoxid]] [[de:Magnesiumoxid]] [[es:Magnesia (mineral)]] [[fr:Oxyde de magnésium]] [[it:Ossido di magnesio]] [[hu:Magnézium-oxid]] [[nl:Magnesiumoxide]] [[ja:酸化マグネシウム]] [[no:Magnesiumoksid]] [[nn:Magnesiumoksid]] [[pl:Tlenek magnezu]] [[pt:Óxido de magnésio]] [[qu:Qunta]] [[ru:Оксид магния]] [[simple:Magnesium oxide]] [[sr:Магнезијум оксид]] [[sv:Magnesiumoxid]] [[vi:Ôxít magiê]] [[zh:氧化镁]]