Magnesium oxide: Difference between revisions
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| url = http://www.newscientist.com/article/mg20727791.100-emission-control-turning-carbon-trash-into-treasure.html?full=true |pages= 48–51|volume=2779 |
| url = http://www.newscientist.com/article/mg20727791.100-emission-control-turning-carbon-trash-into-treasure.html?full=true |pages= 48–51|volume=2779 |
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| title = Emission control: Turning carbon trash into treasure |
| title = Emission control: Turning carbon trash into treasure |
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| first = |
| first = Bill |
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| last = |
| last = Clinton |
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| date = 25 September 2010 (updated 1 October 2010) |
| date = 25 September 2010 (updated 1 October 2010) |
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| journal = New Scientist |
| journal = New Scientist |
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===Medical=== |
===Medical=== |
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LIL B "The BaseGod" was here and I own swag woo!!!! |
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In medicine, magnesium oxide is used for relief of 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/meds/a601074.html Magnesium Oxide]. MedlinePlus. Last reviewed 02/01/2009</ref> In quantities sufficient to obtain a laxative effect, side effects of long-term use include [[enterolith]]s resulting in [[bowel obstruction]].<ref>{{cite journal |
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| author = Tatekawa Y |
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| title = Small bowel obstruction caused by a medication bezoar: report of a case |
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| journal = Surgery today |
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| volume = 26 |
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| issue = 1 |
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| pages = 68–70 |
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| year = 1996 |
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| pmid = 8680127 |
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| doi = 10.1007/BF00311997 |
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| url = |
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| author-separator = , |
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| author2 = Nakatani K |
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| author3 = Ishii H |
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| display-authors = 3 |
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| last4 = Paku |
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| first4 = Shuuichi |
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| last5 = Kasamatsu |
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| first5 = Minoru |
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| last6 = Sekiya |
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| first6 = Nao |
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| last7 = Nakano |
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| first7 = Hiroshige |
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}}</ref> |
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===Other=== |
===Other=== |
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Revision as of 17:49, 23 February 2012
| |
| |
| Names | |
|---|---|
| IUPAC name
Magnesium oxide
| |
| Other names
Magnesia
Periclase | |
| Identifiers | |
| ChEMBL | |
| ECHA InfoCard | 100.013.793 |
| E number | E530 (acidity regulators, ...) |
PubChem CID
|
|
| RTECS number |
|
CompTox Dashboard (EPA)
|
|
| Properties | |
| MgO | |
| Molar mass | 40.3044 g/mol |
| Appearance | White powder |
| Odor | Odorless |
| Density | 3.58 g/cm3 |
| Melting point | 2,852 °C (5,166 °F; 3,125 K) |
| Boiling point | 3,600 °C (6,510 °F; 3,870 K) |
| 0.086 g/L[1] | |
| Solubility | Soluble in acid, ammonia insoluble in alcohol |
| Band gap | 7.8 eV [2] |
Refractive index (nD)
|
1.736 |
| Structure | |
| Halite (cubic), cF8 | |
| Fm3m, No. 225 | |
| Octahedral (Mg2+); octahedral (O2–) | |
| Thermochemistry | |
Std molar
entropy (S⦵298) |
27 J·mol−1·K−1[3] |
Std enthalpy of
formation (ΔfH⦵298) |
-602 kJ·mol−1[3] |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
|
Metal fume fever, Irritant |
| NFPA 704 (fire diamond) | |
| Flash point | Non-flammable |
| Related compounds | |
Other anions
|
Magnesium sulfide |
Other cations
|
Beryllium oxide Calcium oxide Strontium oxide Barium oxide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
Magnesium oxide (MgO), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of Template:MagnesiumTemplate:Oxygen and consists of a lattice of Mg2+ ions and O2– ions held together by ionic bonds. Magnesium hydroxide forms in the presence of water (MgO + H2O → Mg(OH)2), but it can be reversed by heating it to separate moisture.
Magnesium oxide was historically known as magnesia alba (literally, the white mineral from Magnesia), to differentiate it from magnesia negra, a black mineral containing what is now known as manganese.
Applications
A refractory material is one that is physically and chemically stable at high temperatures. "By far the largest consumer of magnesia worldwide is the refractory industry, which consumed about 56% of the magnesia in the United States in 2004, the remaining 44% being used in agricultural, chemical, construction, environmental, and other industrial applications."[4]
Cement
MgO is one of the raw materials for making Portland cement in dry process plants. If too much MgO is added, the cement may become expansive. Production of MgO-based cement using serpentinite and waste CO2 (as opposed to conventional CaO-based cement using fossil fuels) may reduce anthropogenic emissions of CO2.[5]
Desiccant
MgO is relatively poor dessicant, but because it neutralizes sulfur oxide acids created by oxidation of Kraft-processed papers, it is used by many libraries for preserving books.[6]
Medical
LIL B "The BaseGod" was here and I own swag woo!!!!
Other
- MgO is used as an insulator in industrial cables, as a basic refractory material for crucibles and as a principal fireproofing ingredient in construction materials. As a construction material, magnesium oxide wallboards have several attractive characteristics: fire resistance, moisture resistance, mold and mildew resistance, and strength.
- It is used as a reference white color in colorimetry, owing to its good diffusing and reflectivity properties.[7] It may be smoked onto the surface of an opaque material to form an integrating sphere.
- It is used extensively in heating as a component of "CalRod"-styled heating elements. 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.
- Pressed MgO is used as an optical material. It is transparent from 0.3 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.[8]
- It is packed around transuranic waste at the Waste Isolation Pilot Plant, to control the solubility of radionuclides.[9]
- An aerosolized solution of MgO is used in library science and collections management for the deacidification of at-risk paper items. In this process, the alkalinity of MgO (and similar compounds) neutralizes the relatively high acidity characteristic of low-quality paper, thus slowing the rate of deterioration.[10]
- It is also used as a protective coating in plasma displays.
Precautions
Magnesium oxide is easily made by burning magnesium ribbon which oxidizes in a bright white light, resulting in a powder. However, the bright flame is very hard to extinguish and it emits a harmful intensity of UV light. Inhalation of magnesium oxide fumes can cause metal fume fever.[11]
See also
References
- ^ Material Safety Data Sheet. Magnesium oxide
- ^ O. E. Taurian; et al. (1985). "Self-consistent electronic structures of MgO and SrO". Solid State Communications. 55 (4): 351. doi:10.1016/0038-1098(85)90622-2.
{{cite journal}}: Unknown parameter|author-separator=ignored (help) - ^ a b Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A22. ISBN 061894690X.
- ^ Mark A. Shand (2006). The chemistry and technology of magnesia. John Wiley and Sons. ISBN 978-0-471-65603-6. Retrieved 10 September 2011.
- ^ Clinton, Bill (25 September 2010 (updated 1 October 2010)). "Emission control: Turning carbon trash into treasure". New Scientist. 2779: 48–51. Retrieved 4 Oct 2010.
{{cite journal}}: Check date values in:|date=(help) - ^ Ferro, Shaunacy (6 January 2012). "FYI: Why Do Libraries Have That Smell?". Retrieved 19 Jan 2012.
{{cite journal}}: Cite journal requires|journal=(help); Unknown parameter|publischer=ignored (help) - ^ Tellex, Peter A. (1955). "Reflectance of Magnesium Oxide". JOSA. 45 (1): 19. doi:10.1364/JOSA.45.000019.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Index of Refraction of Magnesium Oxide Robert E. Stephens and Irving H. Malitson
- ^ wipp.energy.gov Step-By-Step Guide for Waste Handling at WIPP. Waste Isolation Pilot Plant. wipp.energy.gov
- ^ "Mass Deacidification: Saving the Written Word". Library of Congress. Retrieved 26 September 2011.
- ^ National Pollutant Inventory – Magnesium Oxide Fume Fact Sheet