Sodium chloride 80207 226163609 2008-07-17T02:55:04Z Montco 882433 -sfbsc linkspam ''For sodium chloride in the diet, see [[salt]].'' {{Chembox new | Name = Sodium chloride | ImageFile = Halite(Salt)USGOV.jpg | ImageFile1 = Sodium-chloride-3D-ionic.png | IUPACName = Sodium chloride | OtherNames = Common salt; [[halite]]; [[table salt]] | Section1 = {{Chembox Identifiers | CASNo = 7647-14-5 | RTECS = VZ4725000 }} | Section2 = {{Chembox Properties | Formula = [[Sodium|Na]][[Chlorine|Cl]] | MolarMass = 58.44277 g/mol | Appearance = White or colorless crystals or powder | Solubility = 35.9 g/100 mL (25 °C) | Density = 2.16 g/cm³, solid | MeltingPt = 801 °C | BoilingPt = 1465 °C (1738 K) | Index of Refraction = 1.544 (589 nm) }} | Section3 = {{Chembox Structure | Coordination = Octahedral | Structure = [[Cubic crystal system|Face centered cubic]] }} | Section7 = {{Chembox Hazards | MainHazards = Might sting eyes, prolonged exposure to flame and air liberates strong acid | NFPA-H = 1 | NFPA-F = 0 | NFPA-R = 1 | FlashPt = Non-flammable | RPhrases = R36 | SPhrases = S15,S25,S47 }} | Section8 = {{Chembox Related | OtherAnions = [[Sodium fluoride|NaF]], [[Sodium bromide|NaBr]], [[Sodium iodide|NaI]] | OtherCations = [[Lithium chloride|LiCl]], [[Potassium chloride|KCl]], [[Rubidium chloride|RbCl]],<br />[[Caesium chloride|CsCl]], [[Magnesium chloride|MgCl<sub>2</sub>]], [[Calcium chloride|CaCl<sub>2</sub>]] | Function = [[salt]]s | OtherFunctn = [[Sodium acetate]] }} }} '''Sodium chloride''', also known as ''' common salt''', '''table salt''', or [[halite]], is a [[chemical compound]] with the [[chemical formula|formula]] [[Sodium|Na]][[Chlorine|Cl]]. Sodium chloride is the [[salt (chemistry)|salt]] most responsible for the salinity of the [[ocean]] and of the [[extracellular fluid]] of many multicellular [[organism]]s. As the major ingredient in [[edible salt]], it is commonly used as a [[condiment]] and food [[preservative]]. In one gram of sodium chloride, there are approximately 0.3933 grams of sodium, and 0.6067 grams of chlorine. ==Production and use== Salt is currently [[Mass production|mass-produced]] by [[evaporation]] of [[seawater]] or [[brine]] from other sources, such as brine wells and [[salt lake (geography)|salt lake]]s, and by [[salt mine|mining]] '''rock salt''', called [[halite]]. In 2002, world production was estimated at 210 million metric tonnes, the top five producers being the United States (40.3 million tonnes), China (32.9), Germany (17.7), India (14.5), and Canada (12.3).<ref>Susan R. Feldman. Sodium chloride. ''Kirk-Othmer Encyclopedia of Chemical Technology''. John Wiley & Sons, Inc. Published online '''2005'''. {{doi|10.1002/0471238961.1915040902051820.a01.pub2}}</ref> As well as the familiar uses of salt in [[cooking]], salt is used in many applications, from [[manufacturing]] pulp and paper to setting dyes in textiles and fabric, to producing [[soap]]s, [[detergent]]s, and other bath products. In cold countries, large quantities of rock salt are used to help clear highways of ice during winter, although "Road Salt" loses its melting ability at temperatures below -15°C to -20°C (5°F to -4°F). Sodium chloride is sometimes used as a cheap and safe [[desiccant]] due to its [[hygroscopic]] properties, making [[Salting (food)|salting]] an effective method of [[food preservation]] historically. Even though more effective desiccants are available, few are safe for humans to ingest. <gallery> Image:Dead-Sea---Salt-Evaporation-Ponds.jpg| [[Israel]]i and [[Jordan]]ian salt evaporation ponds at the south end of the [[Dead Sea]] Image:Piles of Salt Salar de Uyuni Bolivia Luca Galuzzi 2006 a.jpg|Mounds of salt, [[Salar de Uyuni]], [[Bolivia]]. </gallery> <br /> <gallery> Image:Salt mine 0096.jpg|Modern rock salt mine near [[Mount Morris, New York|Mount Morris]], [[New York]]. Image:Aigues-Mortes2.jpg|Evaporation lagoons, [[Aigues-Mortes]], France </gallery> {| class="toccolours" border="1" align="left" style="margin: 1em; border-collapse: collapse;" ! {{chembox header}} | Solubility of NaCl in various solvents<br/ >(g NaCl / 100 g of solvent at 25 °C) |- | [[Water (molecule)|H<sub>2</sub>O]] || 36 |- | [[Ammonia|Liquid ammonia]] || 3.02 |- | [[Methanol]] || 1.4 |- | [[Sulfolane]] || 0.005 |- | [[Formic acid]] || 5.2 |- | [[Acetone]] || 0.000042 |- | [[Formamide]] || 9.4 |- | [[Acetonitrile]] || 0.0003 |- | [[Dimethylformamide]] || 0.04 |- | align="center" colspan="2" | Reference:<br />Burgess, J. ''Metal Ions in Solution''<br />(Ellis Horwood, New York, 1978)<br />ISBN 0-85312-027-7 |} ===Synthetic uses=== Salt is also the raw material used to produce [[chlorine]] which itself is required for the production of many modern materials including [[Polyvinyl chloride|PVC]] and [[pesticide]]s. Industrially, elemental chlorine is usually produced by the [[electrolysis]] of sodium chloride dissolved in water. Along with chlorine, this [[chloralkali process]] yields [[hydrogen]] gas and [[sodium hydroxide]], according to the [[chemical equation]] :2NaCl + 2H<sub>2</sub>O → Cl<sub>2</sub> + H<sub>2</sub> + 2NaOH Sodium metal is produced commercially through the electrolysis of liquid sodium chloride. This is done in a [[Downs Cell|Down's cell]] in which sodium chloride is mixed with calcium chloride to lower the melting point below 700 °C. As calcium is more electropositive than sodium, no calcium will be formed at the cathode. This method is less expensive than the previous method of electrolyzing sodium hydroxide. Sodium chloride is used in other chemical processes for the large-scale production of compounds containing sodium or chlorine. In the [[Solvay process]], sodium chloride is used for producing [[sodium carbonate]] and [[calcium chloride]]. In the [[Mannheim process]] and in the [[Hargreaves process]], it is used for the production of [[sodium sulfate]] and [[hydrochloric acid]]. ===Biological uses=== Many [[microorganism]]s cannot live in an overly salty environment: water is drawn out of their [[cell (biology)|cells]] by [[osmosis]]. For this reason salt is used to [[Food preservation|preserve]] some foods, such as smoked bacon or fish and can also be used to detach [[leech]]es that have attached themselves to feed. It has also been used to disinfect wounds. ===Household uses=== Since at least [[medieval]] times, people have used salt as a cleansing agent rubbed on household surfaces. ==Biological functions== In humans, a high-salt intake has long been known to generally raise blood pressure, especially in certain individuals. More recently, it was demonstrated to attenuate Nitric Oxide production. Nitric oxide (NO) contributes to vessel homeostasis by inhibiting vascular smooth muscle contraction and growth, platelet aggregation, and leukocyte adhesion to the endothelium [[http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ProduktNr=223997&Ausgabe=228460&ArtikelNr=63555]] ==Crystal structure== [[Image:NaCl polyhedra.png|240px|thumb|right|The crystal structure of sodium chloride. Each atom has six nearest neighbors, with [[octahedral geometry]].]] Sodium chloride forms [[crystal]]s with cubic [[symmetry]]. In these, the larger [[Chlorine|chloride]] [[ion]]s, shown to the right as green spheres, are arranged in a cubic [[close-packing]], while the smaller [[sodium]] ions, shown to the right as silver spheres, fill the octahedral gaps between them. Each ion is surrounded by six ions of the other kind. This same basic structure is found in many other [[mineral]]s, and is known as the [[halite]] structure. This arrangement is known as ''[[cubic crystal system|cubic close packed]]'' (ccp). It can be represented as two interpenetrating face-centered cubic (fcc) lattices, or one fcc lattice with a two atom basis. It is most commonly known as the rocksalt crystal structure. It is held together with an [[ionic bond]] and [[electrostatic force]]s. ==Road salt== While salt was once a scarce commodity in history, industrialized production has now made salt plentiful. About 51% of world output is now used by cold countries to [[deicing|de-ice]] roads in winter, both in [[grit bin]]s and spread by [[winter service vehicle]]s. This works because salt and water form an [[eutectic]] mixture. Adding salt to water will lower the freezing temperature of the water, depending on the concentration. The salinity (S) of water is measured as grams salt per kilogram (1000g) water, and the freezing temperatures are as follows. {| class="wikitable" |- | S(g/kg) | 0 | 10 | 20 | 24.7 | 30 | 35 |- | T(freezing) (C) | 0 | -0.5 | -1.08 | -1.33 | -1.63 | -1.91 |} ===Additives=== Table salt sold for consumption today is not pure sodium chloride. In [[1911]] [[magnesium carbonate]] was first added to salt to make it flow more freely.<ref>{{cite web |title=Morton Salt FAQ |url=http://www.mortonsalt.com/faqs/index.html#q3 |access-date = 2007-05-12 }}</ref> In [[1924]] trace amounts of [[iodine]] in form of sodium iodide, [[potassium iodide]] or [[potassium iodate]] were first added, to reduce the incidence of simple [[Goitre|goiter]].<ref>{{cite journal |author=Markel H |title="When it rains it pours": endemic goiter, iodized salt, and David Murray Cowie, MD |journal=American journal of public health |volume=77 |issue=2 |pages=219–29 |year=1987 | url = http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1646845 | pmid=3541654}}</ref> Salt for de-icing in the UK typically contains sodium [[hexacyanoferrate]] (II) at less than 100ppm as an anti-caking agent. In recent years this additive has also been used in table salt. ===Common chemicals=== Chemicals used in de-icing salts are mostly found to be sodium chloride (NaCl) or [[calcium chloride]] (CaCl<sub>2</sub>). Both are similar and are effective in de-icing roads. When these chemicals are produced, they are mined/made, crushed to fine granules, then treated with an anti-caking agent. Adding salt lowers the freezing point of the water, which allows the liquid to be stable at lower temperatures and allows the ice to melt. Alternative de-icing chemicals have also been used. Chemicals such as [[calcium magnesium acetate]] and [[potassium formate]] are being produced. These chemicals have few of the negative chemical effects on the environment commonly associated with NaCl and CaCl<sub>2</sub>.<ref>{{cite press release | publisher = Finnish Environment Institute | title = Migration of alternative de-icing chemicals in aquifers (MIDAS) | url = http://www.ymparisto.fi/default.asp?contentid=216408&lan=EN | date = 1/9/2007}}</ref><ref>{{cite press release | publisher = Finnish Environment Institute | title = Alternative de-icer found | url = http://www.ymparisto.fi/default.asp?contentid=60509&lan=en | date = 2/10/2004}}</ref> ==See also== {{Cookbook|Salt}} {{Commons2|Sodium chloride}} *[[Biosalinity]] *[[Black salt]] *[[Edible salt]] *[[Halite]], the mineral form of sodium chloride *[[Salinity]] *[[Soap]] *[[Salting the earth]] ==References== {{reflist}} ==External links== *[http://www.saltsense.co.uk/deicing-environ01.htm The Salt Manufacturers Association] website *[http://www.saltinstitute.org Salt Institute] website *[http://salt.org.il/news_arch.htm Salt Archive] website *[http://users.tpg.com.au/terrett/Downloads/snarfevsCCPLatticerotate.avi Video] of rotating rock salt unit cell (divx, 378kb) *[http://minerals.usgs.gov/minerals/pubs/commodity/salt/ Salt] [[United States Geological Survey]] Statistics and Information *[http://www.usroads.com/journals/p/rmj/9712/rm971202.htm US Road Management] website *[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8800478&dopt=Abstract Salt Intake in Cold Weather] [[Category:Chlorides]] [[Category:Sodium compounds]] [[Category:Edible salt]] [[Category:Metal halides]] [[Category:Salts]] [[Category:Granular materials]] [[Category:Preservatives]] [[Category:Antiseptics]] [[Category:Snow removal]] [[am:ጨው]] [[ar:كلوريد صوديوم]] [[az:Natrium Xlorid]] [[bg:Натриев хлорид]] [[ca:Clorur de sodi]] [[cs:Chlorid sodný]] [[cy:Halen]] [[da:Natriumklorid]] [[de:Natriumchlorid]] [[et:Naatriumkloriid]] [[es:Cloruro de sodio]] [[eo:Natria klorido]] [[fa:سدیم کلرید]] [[fr:Chlorure de sodium]] [[gl:Cloruro de sodio]] [[ko:염화 나트륨]] [[hr:Kuhinjska sol]] [[id:Natrium klorida]] [[is:Borðsalt]] [[it:Cloruro di sodio]] [[he:מלח בישול]] [[la:Natrii Chloridum]] [[lv:Nātrija hlorīds]] [[lt:Natrio chloridas]] [[hu:Nátrium-klorid]] [[ms:Natrium Klorida]] [[nl:Natriumchloride]] [[ja:塩化ナトリウム]] [[no:Natriumklorid]] [[nrm:Sé (NaCl)]] [[nds:Natriumchlorid]] [[pl:Chlorek sodu]] [[pt:Cloreto de sódio]] [[qu:Yanuna kachi]] [[ru:Хлорид натрия]] [[scn:Cloruru di sodiu]] [[simple:Table salt]] [[sk:Chlorid sodný]] [[sr:Кухињска со]] [[sv:Natriumklorid]] [[th:โซเดียมคลอไรด์]] [[vi:Clorua natri]] [[uk:Хлорид натрію]] [[zh:氯化钠]]