50-529: (Redirected from SO-2 ) [REDACTED] Look up so2 in Wiktionary, the free dictionary. SO2 or SO 2 may refer to: Science [ edit ] Sulfur dioxide (SO 2 ), a colorless gas with a pungent smell Sulfonyl group (R-SO 2 -R), a functional group found primarily in sulfones, or a substituent SO(2), special orthogonal group of degree 2 in mathematics Oxygen saturation (SO 2 ),
100-420: A dichromate solution, turning the solution from orange to green (Cr (aq)). It can also reduce ferric ions to ferrous. Sulfur dioxide can react with certain 1,3- dienes in a cheletropic reaction to form cyclic sulfones . This reaction is exploited on an industrial scale for the synthesis of sulfolane , which is an important solvent in the petrochemical industry . Sulfur dioxide can bind to metal ions as
150-399: A ligand to form metal sulfur dioxide complexes , typically where the transition metal is in oxidation state 0 or +1. Many different bonding modes (geometries) are recognized, but in most cases, the ligand is monodentate, attached to the metal through sulfur, which can be either planar and pyramidal η . As a η -SO 2 (S-bonded planar) ligand sulfur dioxide functions as a Lewis base using
200-597: A high heat of evaporation , sulfur dioxide is a candidate material for refrigerants. Before the development of chlorofluorocarbons , sulfur dioxide was used as a refrigerant in home refrigerators . Sulfur dioxide content in naturally-released geothermal gasses is measured by the Icelandic Meteorological Office as an indicator of possible volcanic activity. In the United States, the Center for Science in
250-465: A natural satellite of Jupiter , is 90% sulfur dioxide and trace amounts are thought to also exist in the atmosphere of Jupiter . The James Webb Space Telescope has observed the presence of sulfur dioxide on the exoplanet WASP-39b , where it is formed through photochemistry in the planet's atmosphere. As an ice, it is thought to exist in abundance on the Galilean moons —as subliming ice or frost on
300-681: A negative inotropic effect on cardiac output function, thus effectively lowering blood pressure and myocardial oxygen consumption. The vasodilating and bronchodilating effects of sulfur dioxide are mediated via ATP-dependent calcium channels and L-type ("dihydropyridine") calcium channels. Endogenous sulfur dioxide is also a potent antiinflammatory, antioxidant and cytoprotective agent. It lowers blood pressure and slows hypertensive remodeling of blood vessels, especially thickening of their intima. It also regulates lipid metabolism. Endogenous sulfur dioxide also diminishes myocardial damage, caused by isoproterenol adrenergic hyperstimulation, and strengthens
350-458: A preservative for dried apricots, dried figs, and other dried fruits, owing to its antimicrobial properties and ability to prevent oxidation , and is called E 220 when used in this way in Europe. As a preservative, it maintains the colorful appearance of the fruit and prevents rotting . Historically, molasses was "sulfured" as a preservative and also to lighten its color. Treatment of dried fruit
400-423: A winery due to the risk of cork taint , a mixture of SO 2 , water, and citric acid is commonly used to clean and sanitize equipment. Ozone (O 3 ) is now used extensively for sanitizing in wineries due to its efficacy, and because it does not affect the wine or most equipment. Sulfur dioxide is also a good reductant . In the presence of water, sulfur dioxide is able to decolorize substances. Specifically, it
450-484: Is exothermic , and the combustion produces temperatures of 1,000–1,600 °C (1,830–2,910 °F). The significant amount of heat produced is recovered by steam generation that can subsequently be converted to electricity. The combustion of hydrogen sulfide and organosulfur compounds proceeds similarly. For example: The roasting of sulfide ores such as pyrite , sphalerite , and cinnabar (mercury sulfide) also releases SO 2 : A combination of these reactions
500-399: Is a bent molecule with C 2v symmetry point group . A valence bond theory approach considering just s and p orbitals would describe the bonding in terms of resonance between two resonance structures. The sulfur–oxygen bond has a bond order of 1.5. There is support for this simple approach that does not invoke d orbital participation. In terms of electron-counting formalism,
550-401: Is a key component of the planet's global atmospheric sulfur cycle and contributes to global warming . It has been implicated as a key agent in the warming of early Mars , with estimates of concentrations in the lower atmosphere as high as 100 ppm, though it only exists in trace amounts. On both Venus and Mars, as on Earth, its primary source is thought to be volcanic. The atmosphere of Io ,
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#1733114463996600-402: Is a useful reducing bleach for papers and delicate materials such as clothes. This bleaching effect normally does not last very long. Oxygen in the atmosphere reoxidizes the reduced dyes, restoring the color. In municipal wastewater treatment, sulfur dioxide is used to treat chlorinated wastewater prior to release. Sulfur dioxide reduces free and combined chlorine to chloride . Sulfur dioxide
650-457: Is also used to distinguish between British English and that in the rest of the Commonwealth. English in the Commonwealth is diverse, and many regions have developed their own local varieties of the language. In Cyprus , it does not have official status but is widely used as a lingua franca . English is spoken as a first or second language in most of the Commonwealth. Written English in
700-410: Is an intermediate in the production of sulfuric acid, being converted to sulfur trioxide , and then to oleum , which is made into sulfuric acid. Sulfur dioxide for this purpose is made when sulfur combines with oxygen. The method of converting sulfur dioxide to sulfuric acid is called the contact process . Several million tons are produced annually for this purpose. Sulfur dioxide is sometimes used as
750-408: Is different from Wikidata All article disambiguation pages All disambiguation pages Sulfur dioxide Selenium dioxide Tellurium dioxide Polonium dioxide Sulfur dioxide ( IUPAC -recommended spelling) or sulphur dioxide (traditional Commonwealth English ) is the chemical compound with the formula S O 2 . It is a colorless gas with a pungent smell that
800-478: Is fairly soluble in water, and by both IR and Raman spectroscopy; the hypothetical sulfurous acid , H 2 SO 3 , is not present to any extent. However, such solutions do show spectra of the hydrogen sulfite ion, HSO 3 , by reaction with water, and it is in fact the actual reducing agent present: In the beginning of the 20th century sulfur dioxide was used in Buenos Aires as a fumigant to kill rats that carried
850-470: Is in the process of developing) its own standards of usage, often under the influence of local languages. These dialects are sometimes referred to as New Englishes (McArthur, p. 36); most of them inherited non-rhoticity from Southern British English. Several dialects of West African English exist, with a lot of regional variation and some influence from indigenous languages. West African English tends to be syllable-timed , and its phoneme inventory
900-539: Is increasingly being used in the home as the first language. Small communities of native English speakers can be found in Zimbabwe , Botswana , and Namibia ; the dialects spoken are similar to native South African English . Prior to Togo 's admission at the 2022 Commonwealth Heads of Government Meeting , Togolese Foreign Minister Robert Dussey said that he expected Commonwealth membership to provide opportunities for Togolese citizens to learn English , and remarked that
950-467: Is much simpler than that of Received Pronunciation ; this sometimes affects mutual intelligibility with native varieties of English. A distinctive North African English , often with significant influences from Bantu languages such as Swahili , is spoken in countries such as Kenya , Uganda , or Tanzania , particularly in Nairobi and other cities where there is an expanding middle class, for whom English
1000-431: Is often used as a low-temperature solvent/diluent for superacids like magic acid (FSO 3 H/SbF 5 ), allowing for highly reactive species like tert -butyl cation to be observed spectroscopically at low temperature (though tertiary carbocations do react with SO 2 above about −30 °C, and even less reactive solvents like SO 2 ClF must be used at these higher temperatures). Being easily condensed and possessing
1050-748: Is produced biologically as an intermediate in both sulfate-reducing organisms and in sulfur-oxidizing bacteria, as well. The role of sulfur dioxide in mammalian biology is not yet well understood. Sulfur dioxide blocks nerve signals from the pulmonary stretch receptors and abolishes the Hering–Breuer inflation reflex . It is considered that endogenous sulfur dioxide plays a significant physiological role in regulating cardiac and blood vessel function, and aberrant or deficient sulfur dioxide metabolism can contribute to several different cardiovascular diseases, such as arterial hypertension , atherosclerosis , pulmonary arterial hypertension , and stenocardia . It
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#17331144639961100-433: Is produced by the combustion of elemental sulfur . Some sulfur dioxide is also produced by roasting pyrite and other sulfide ores in air. Sulfur dioxide is the product of the burning of sulfur or of burning materials that contain sulfur: To aid combustion, liquified sulfur (140–150 °C (284–302 °F) is sprayed through an atomizing nozzle to generate fine drops of sulfur with a large surface area. The reaction
1150-510: Is responsible for the largest source of sulfur dioxide, volcanic eruptions. These events can release millions of tons of SO 2 . Sulfur dioxide can also be a byproduct in the manufacture of calcium silicate cement; CaSO 4 is heated with coke and sand in this process: Until the 1970s commercial quantities of sulfuric acid and cement were produced by this process in Whitehaven , England. Upon being mixed with shale or marl , and roasted,
1200-424: Is responsible for the odor of burnt matches. It is released naturally by volcanic activity and is produced as a by-product of copper extraction and the burning of sulfur - bearing fossil fuels. Sulfur dioxide is somewhat toxic to humans, although only when inhaled in relatively large quantities for a period of several minutes or more. It was known to medieval alchemists as "volatile spirit of sulfur". SO 2
1250-602: Is still an important compound in winemaking, and is measured in parts per million ( ppm ) in wine. It is present even in so-called unsulfurated wine at concentrations of up to 10 mg/L. It serves as an antibiotic and antioxidant , protecting wine from spoilage by bacteria and oxidation – a phenomenon that leads to the browning of the wine and a loss of cultivar specific flavors. Its antimicrobial action also helps minimize volatile acidity. Wines containing sulfur dioxide are typically labeled with "containing sulfites ". Sulfur dioxide exists in wine in free and bound forms, and
1300-429: Is the active form, while at higher pH more SO 2 is found in the inactive sulfite and bisulfite forms. The molecular SO 2 is active as an antimicrobial and antioxidant, and this is also the form which may be perceived as a pungent odor at high levels. Wines with total SO 2 concentrations below 10 ppm do not require "contains sulfites" on the label by US and EU laws. The upper limit of total SO 2 allowed in wine in
1350-495: Is the product of several waves of immigration and settlement, from Britain, Ireland, France, the United States, and around the world, over a period of more than two centuries. Modern Canadian English has taken significant vocabulary and spelling from the shared political and social institutions of Commonwealth countries. Caribbean English is influenced by the English-based Creole varieties spoken, but they are not one and
1400-410: Is used in the production of sulfuric acid. Sulfur dioxide dissolves in water to give " sulfurous acid ", which cannot be isolated and is instead an acidic solution of bisulfite , and possibly sulfite , ions. Sulfur dioxide is one of the few common acidic yet reducing gases. It turns moist litmus pink (being acidic), then white (due to its bleaching effect). It may be identified by bubbling it through
1450-479: The English language in current and former Commonwealth countries was largely inherited from British colonisation , with some exceptions. English serves as the medium of inter-Commonwealth relations and the language forms part of the common culture of the Commonwealth . Commonwealth English refers to English as practised in the Commonwealth; the term is most often interchangeable with British English , but
1500-648: The Yersinia pestis bacterium, which causes bubonic plague. The application was successful, and the application of this method was extended to other areas in South America. In Buenos Aires, where these apparatuses were known as Sulfurozador , but later also in Rio de Janeiro, New Orleans and San Francisco, the sulfur dioxide treatment machines were brought into the streets to enable extensive disinfection campaigns, with effective results. Sulfur dioxide or its conjugate base bisulfite
1550-613: The proliferation rate of endothelial smooth muscle cells in blood vessels, via lowering the MAPK activity and activating adenylyl cyclase and protein kinase A . Smooth muscle cell proliferation is one of important mechanisms of hypertensive remodeling of blood vessels and their stenosis , so it is an important pathogenetic mechanism in arterial hypertension and atherosclerosis. Endogenous sulfur dioxide in low concentrations causes endothelium-dependent vasodilation . In higher concentrations it causes endothelium-independent vasodilation and has
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1600-517: The 18th century, with the colonisation of Australasia and South Africa. Australian English and New Zealand English are closely related to each other and share some similarities with South African English (though it has unique influences from indigenous African languages, and Dutch influences it inherited along with the development of Afrikaans from Dutch). Canadian English contains elements of British English and American English , as well as many Canadianisms and some French influences. It
1650-576: The British, World War II Special Operations Executive Other uses [ edit ] SO2 (album) , a 2010 album by Shinichi Osawa See also [ edit ] [REDACTED] Search for "so2" on Misplaced Pages. Oxygen saturation (medicine) (SaO 2 , SvO 2 , StO 2 , SpO 2 ) All pages with titles beginning with SO2 All pages with titles containing SO2 Soso (disambiguation) Soo (disambiguation) SO (disambiguation) [REDACTED] Topics referred to by
1700-445: The Commonwealth, although comparatively very few speakers of Indian English are first-language speakers. The same is true of English spoken in other parts of South Asia , e.g. Pakistani English , Sri Lankan English , Bangladeshi English and Myanmar English . South Asian English phonology is highly variable; stress, rhythm and intonation are generally different from those of native varieties. There are also several peculiarities at
1750-695: The Public Interest lists the two food preservatives, sulfur dioxide and sodium bisulfite , as being safe for human consumption except for certain asthmatic individuals who may be sensitive to them, especially in large amounts. Symptoms of sensitivity to sulfiting agents, including sulfur dioxide, manifest as potentially life-threatening trouble breathing within minutes of ingestion. Sulphites may also cause symptoms in non-asthmatic individuals, namely dermatitis , urticaria , flushing , hypotension , abdominal pain and diarrhea, and even life-threatening anaphylaxis . Commonwealth English The use of
1800-498: The US is 350 ppm; in the EU it is 160 ppm for red wines and 210 ppm for white and rosé wines. In low concentrations, SO 2 is mostly undetectable in wine, but at free SO 2 concentrations over 50 ppm, SO 2 becomes evident in the smell and taste of wine. SO 2 is also a very important compound in winery sanitation. Wineries and equipment must be kept clean, and because bleach cannot be used in
1850-506: The action of aqueous base on sulfur dioxide: Sulfur dioxide is a mild but useful reducing agent . It is oxidized by halogens to give the sulfuryl halides, such as sulfuryl chloride : Sulfur dioxide is the oxidising agent in the Claus process , which is conducted on a large scale in oil refineries . Here, sulfur dioxide is reduced by hydrogen sulfide to give elemental sulfur: The sequential oxidation of sulfur dioxide followed by its hydration
1900-421: The combinations are referred to as total SO 2 . Binding, for instance to the carbonyl group of acetaldehyde , varies with the wine in question. The free form exists in equilibrium between molecular SO 2 (as a dissolved gas) and bisulfite ion, which is in turn in equilibrium with sulfite ion. These equilibria depend on the pH of the wine. Lower pH shifts the equilibrium towards molecular (gaseous) SO 2 , which
1950-534: The concentration of oxygen dissolved in a medium S2 (star) or S0–2, a star near the central black hole at the center of the Milky Way 2015 SO 2 or 2015 SO2, an Aten asteroid Military and police [ edit ] SO2, a staff officer of the second class, often a commissioned officer of lieutenant commander, major or squadron leader rank SO2, a London Metropolitan Police Specialist Operations command division Special Operations 2 – Operational, of
2000-581: The country sought closer ties with the Anglophone world . Hong Kong ceased to be part of the Commonwealth (by virtue of being a British territory) in 1997. Nonetheless, the English language there still enjoys status as an official language. English was introduced into the subcontinent by the British Raj . Among the partitioned post-independent countries, India has the largest English-speaking population in
2050-621: The current and former Commonwealth generally favours British English spelling as opposed to American English , with some exceptions, particularly in Canada, where there are strong influences from neighbouring American English. Few Commonwealth countries besides Australia, Canada, South Africa, and the United Kingdom have produced their own English dictionaries and style guides , and may rely on those produced in other countries. Southern Hemisphere native varieties of English began to develop during
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2100-420: The lone pair on S. SO 2 functions as a Lewis acids in its η -SO 2 (S-bonded pyramidal) bonding mode with metals and in its 1:1 adducts with Lewis bases such as dimethylacetamide and trimethyl amine . When bonding to Lewis bases the acid parameters of SO 2 are E A = 0.51 and E A = 1.56. The overarching, dominant use of sulfur dioxide is in the production of sulfuric acid . Sulfur dioxide
2150-421: The myocardial antioxidant defense reserve. Sulfur dioxide is a versatile inert solvent widely used for dissolving highly oxidizing salts. It is also used occasionally as a source of the sulfonyl group in organic synthesis . Treatment of aryl diazonium salts with sulfur dioxide and cuprous chloride yields the corresponding aryl sulfonyl chloride, for example: As a result of its very low Lewis basicity , it
2200-448: The same term This disambiguation page lists articles associated with the same title formed as a letter–number combination. If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=SO2&oldid=1250503784 " Category : Letter–number combination disambiguation pages Hidden categories: Short description
2250-706: The same. There is a great deal of variation in the way English is spoken, with a "Standard English" at one end of a bipolar linguistic continuum and Creole languages at the other. These dialects have roots in 17th-century British and Irish English , and African languages , plus localised influences from other colonial languages including French, Spanish, and Dutch; unlike most native varieties of English, West Indian dialects often tend to be syllable-timed rather than stress-timed . Second-language varieties of English in Africa and Asia have often undergone " indigenisation "; that is, each English-speaking community has developed (or
2300-510: The sulfate liberated sulfur dioxide gas, used in sulfuric acid production, the reaction also produced calcium silicate, a precursor in cement production. On a laboratory scale, the action of hot concentrated sulfuric acid on copper turnings produces sulfur dioxide. Tin also reacts with concentrated sulfuric acid but it produces tin(II) sulfate which can later be pyrolyzed at 360 °C into tin dioxide and dry sulfur dioxide. The reverse reaction occurs upon acidification: Sulfites results by
2350-471: The sulfur atom has an oxidation state of +4 and a formal charge of +1. Sulfur dioxide is found on Earth and exists in very small concentrations in the atmosphere at about 15 ppb . On other planets, sulfur dioxide can be found in various concentrations, the most significant being the atmosphere of Venus , where it is the third-most abundant atmospheric gas at 150 ppm. There, it reacts with water to form clouds of Sulfurous acid (SO2 + H2O ⇌ HSO−3+ H+), and
2400-565: The trailing hemisphere of Io , and in the crust and mantle of Europa , Ganymede , and Callisto , possibly also in liquid form and readily reacting with water. Sulfur dioxide is primarily produced for sulfuric acid manufacture (see contact process , but other processes predated that at least since 16th century ). In the United States in 1979, 23.6 million metric tons (26 million U.S. short tons) of sulfur dioxide were used in this way, compared with 150,000 metric tons (165,347 U.S. short tons) used for other purposes. Most sulfur dioxide
2450-572: Was shown that in children with pulmonary arterial hypertension due to congenital heart diseases the level of homocysteine is higher and the level of endogenous sulfur dioxide is lower than in normal control children. Moreover, these biochemical parameters strongly correlated to the severity of pulmonary arterial hypertension. Authors considered homocysteine to be one of useful biochemical markers of disease severity and sulfur dioxide metabolism to be one of potential therapeutic targets in those patients. Endogenous sulfur dioxide also has been shown to lower
2500-463: Was usually done outdoors, by igniting sublimed sulfur and burning in an enclosed space with the fruits. Fruits may be sulfured by dipping them into an either sodium bisulfite , sodium sulfite or sodium metabisulfite . Sulfur dioxide was first used in winemaking by the Romans, when they discovered that burning sulfur candles inside empty wine vessels keeps them fresh and free from vinegar smell. It
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