Properties

Magnesium oxide
General
Name	Magnesium oxide
Chemical formula	MgO
Common Reaction	2Mg + O2 → 2MgO
Appearance	White, Powder
Physical
Formula weight	40.3044 g/mol
Melting point	3073 K (2800 °C)
Boiling point	3873 K (3600 °C)
Density	3.58 kg/dm3
Crystal structure	Cubic FCC
Solubility	0.00062 g in 100 g water
Thermochemistry
ΔfH0liquid	? kJ/mol
ΔfH0solid	-601 kJ/mol
S0solid	32.51 J/(mol·K)
Misc.
Thermal conductivity	42 W m-1 K-1 at 0 °C
Coefficient of thermal expansion[1]	9.84 ×10-6/K at 0 °C
Specific heat capacity	877 J kg-1 K-1
Dielectric constant	9.65 at 1 MHz
Young's modulus	250 GPa
Shear Modulus	155 GPa
Bulk modulus	155 GPa
Poisson's ratio	0.18
Safety
Ingestion	Used as an antacid and/or a laxative. Available over-the-counter.
Inhalation	Causes irritation of upper respiratory tract.
Skin	Causes irritation.
Eyes	Causes irritation.
SI units were used where possible. Unless otherwise stated, standard conditions were used. Disclaimer and references Image File history File links Download high-resolution version (637x615, 56 KB) A sample of magnesium oxide. ... This article or section does not cite any references or sources. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white solid at room temp Standard atomic weight 24. ... An oxide is a chemical compound containing an oxygen atom and other elements. ... Color is an important part of the visual arts. ... ... The mole (symbol: mol) is the SI base unit that measures an amount of substance. ... The melting point of a crystalline solid is the temperature at which it changes state from solid to liquid. ... The kelvin (symbol: K) is a unit increment of temperature and is one of the seven SI base units. ... Celsius is, or relates to, the Celsius temperature scale (previously known as the centigrade scale). ... The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid at a given pressure. ... In physics, density is mass m per unit volume V. For the common case of a homogeneous substance, it is expressed as: where, in SI units: ρ (rho) is the density of the substance, measured in kg·m-3 m is the mass of the substance, measured in kg V is... The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S. It was assigned to the United States in 1889 and is periodically recertified and traceable to the primary international standard, The Kilogram, held at the Bureau International des Poids et... A decimetre is a measurement of length, measuring 10 centimetres or one-tenth of a metre millimetre << centimetre << decimetre << metre << kilometre ... Enargite crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... Solubility refers to the ability for a given substance, the solute, to dissolve in a solvent. ... BIC pen cap, about 1 gram. ... The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy that accompanies the formation of 1 mole of a substance in its standard state from its constituent elements in their standard states (the most stable form of the element at 1 atmosphere... The joule (IPA pronunciation: or ) (symbol: J) is the SI unit of energy. ... The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy that accompanies the formation of 1 mole of a substance in its standard state from its constituent elements in their standard states (the most stable form of the element at 1 atmosphere... In chemistry, the standard molar entropy is the entropy content of one mole of substance, under conditions of standard temperature and pressure. ... In physics, thermal conductivity, k, is the intensive property of a material that indicates its ability to conduct heat. ... During heat transfer, the energy that is stored in the intermolecular bonds between atoms changes. ... Specific heat capacity, also known simply as specific heat (Symbol: C or c) is the measure of the heat energy required to raise the temperature of a given amount of a substance by one degree. ... The relative dielectric constant of a material under given conditions is a measure of the extent to which it concentrates electrostatic lines of flux. ... MegaHertz (MHz) is the name given to one million (106) Hertz, a measure of frequency. ... In solid mechanics, Youngs modulus (E) is a measure of the stiffness of a given material. ... The gigapascal, symbol GPa is an SI unit of pressure. ... The bulk modulus (K) of a substance essentially measures the substances resistance to uniform compression. ... Figure 1: Rectangular specimen subject to compression, with Poissons ratio circa 0. ... Look up si, Si, SI in Wiktionary, the free dictionary. ... Temperature and air pressure can vary from one place to another on the Earth, and can also vary in the same place with time. ... This page refers to the data given in chemical compound property tables. ...

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 MgO. It is formed by an ionic bond between one magnesium and one oxygen atom. Minerals are natural compounds formed through geological processes. ... Periclase occurs naturally in contact metamorphic rocks and is a major component of most basic refractory bricks. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white solid at room temp Standard atomic weight 24. ... An oxide is a chemical compound containing an oxygen atom and other elements. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white solid at room temp Standard atomic weight 24. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ...

Applications

It is used by many libraries for preserving books, and as an insulator in industrial cables. It is also used as a medication to relieve heartburn, sore stomach, or acid indigestion. Medical uses of magnesium oxide also include using it as a short-term laxative, or used to supplement a diet with magnesium. PVC-sheathed MICC cable. ...

Magnesium oxide is used as a basic refractory material for lining crucibles. The term refractory can refer to multiple things: A refractory clergyman is one who refused to swear an oath to the French Revolution-era French state under the Civil Constitution of the Clergy. ...

Magnesium oxide is a principal ingredient in construction materials used for fireproofing.

It is used as a reference white colour in colorimetry. The emissivity value is about 0.9 This article or section is not written in the formal tone expected of an encyclopedia article. ... The emissivity of a material (usually written ) is the ratio of energy radiated by the material to energy radiated by a black body at the same temperature. ...

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. 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 infra-red optics. The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. ... Eastman Kodak Company (NYSE: EK) is an American multinational public company producing photographic materials and equipment. ...

Magnesium oxide (electrical grade) is used extensively in electrical heating industry. 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 di-electric 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 is not used now.

Magnesium oxide is also used in animal feeding industry and there are special grades available. MgO is hygroscopic in nature and care must be taken to protect it from moisture. Magnesium hydroxide (Mg(OH)₂) which forms in the presence of water can be reversed by heating to separate moisture. It has been suggested that this article or section be merged with Milk of Magnesia. ...

In medicine, magnesium oxide is used as a magnesium supplement, to improve symptoms of indigestion, or as a short-term laxative (to evacuate bowels prior to some surgeries). Side effects may include nausea and cramping.

Precautions

Inhalation of magnesium oxide fumes can cause metal fume fever. This article or section does not adequately cite its references or sources. ...

See also

Related materials calcium oxide, barium oxide, Magnesium sulfide. Calcium oxide (CaO), commonly known as lime, quicklime or burnt lime, is a widely used chemical compound. ... ... Magnesium sulfide (MgS) is formed by heating sulfur and magnesium. ...

References

1. ^ G. K White, J. Phys D, 1973, 6, 2070

External links

• National Pollutant Inventory - Magnesium Oxide Fume Fact Sheet
• NIH medicinal use
• Data page at UCL
• Ceramic data page at NIST
• Emissivity

• Links to external chemical sources