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72-404: ǀAi-ǀAis features sulfurous thermal hot water springs and forms part of the ǀAi-ǀAis/Richtersveld Transfrontier Park . The springs have been a national monument since 1964. Local legend goes that the hot springs were discovered in 1850 by a nomadic Nama shepherd rounding up stray sheep. The springs originate deep under the riverbed and form an oasis in the extremely arid area. During

144-434: A hydrogen-based economy . It is an alternative to electrolysis , and does not require hydrocarbons like current methods of steam reforming . But note that all of the available energy in the hydrogen so produced is supplied by the heat used to make it. Sulfuric acid is rarely encountered naturally on Earth in anhydrous form, due to its great affinity for water . Dilute sulfuric acid is a constituent of acid rain , which

216-610: A base and can be protonated, forming the [H 3 SO 4 ] ion. Salts of [H 3 SO 4 ] have been prepared (e.g. trihydroxyoxosulfonium hexafluoroantimonate(V) [H 3 SO 4 ] [SbF 6 ] ) using the following reaction in liquid HF : The above reaction is thermodynamically favored due to the high bond enthalpy of the Si–F bond in the side product. Protonation using simply fluoroantimonic acid , however, has met with failure, as pure sulfuric acid undergoes self-ionization to give [H 3 O] ions: which prevents

288-408: A burnt appearance in which the carbon appears much like soot that results from fire. Although less dramatic, the action of the acid on cotton , even in diluted form, destroys the fabric. The reaction with copper(II) sulfate can also demonstrate the dehydration property of sulfuric acid. The blue crystals change into white powder as water is removed. Sulfuric acid reacts with most bases to give

360-465: A component of bad breath odor. Not all organic sulfur compounds smell unpleasant at all concentrations: the sulfur-containing monoterpenoid grapefruit mercaptan in small concentrations is the characteristic scent of grapefruit, but has a generic thiol odor at larger concentrations. Sulfur mustard , a potent vesicant , was used in World War ;I as a disabling agent. Sulfur–sulfur bonds are

432-411: A dehydrating agent, forming the nitronium ion NO + 2 , which is important in nitration reactions involving electrophilic aromatic substitution . This type of reaction, where protonation occurs on an oxygen atom, is important in many organic chemistry reactions, such as Fischer esterification and dehydration of alcohols. When allowed to react with superacids , sulfuric acid can act as

504-572: A major industrial product, especially in automobile tires. Because of the heat and sulfur, the process was named vulcanization , after the Roman god of the forge and volcanism . Being abundantly available in native form, sulfur was known in ancient times and is referred to in the Torah ( Genesis ). English translations of the Christian Bible commonly referred to burning sulfur as "brimstone", giving rise to

576-590: A number of species of fish, including yellowfish and barbel . ǀAi-ǀAis is the end point of a 5-day hiking tour through the Fish River Canyon . Sulfurous This is an accepted version of this page Sulfur (also spelled sulphur in British English ) is a chemical element ; it has symbol S and atomic number 16. It is abundant , multivalent and nonmetallic . Under normal conditions , sulfur atoms form cyclic octatomic molecules with

648-487: A slower rate, so that the acid neutralizing capacity (ANC) of the aquifer can neutralize the produced acid. In such cases, the total dissolved solids (TDS) concentration of the water can be increased from the dissolution of minerals from the acid-neutralization reaction with the minerals. Sulfuric acid is used as a defense by certain marine species, for example, the phaeophyte alga Desmarestia munda (order Desmarestiales ) concentrates sulfuric acid in cell vacuoles. In

720-420: A strong oxidant with powerful dehydrating properties, making it highly corrosive towards other materials, from rocks to metals. Phosphorus pentoxide is a notable exception in that it is not dehydrated by sulfuric acid but, to the contrary, dehydrates sulfuric acid to sulfur trioxide . Upon addition of sulfuric acid to water, a considerable amount of heat is released; thus, the reverse procedure of adding water to

792-416: A structural component used to stiffen rubber, similar to the disulfide bridges that rigidify proteins (see biological below). In the most common type of industrial "curing" or hardening and strengthening of natural rubber , elemental sulfur is heated with the rubber to the point that chemical reactions form disulfide bridges between isoprene units of the polymer. This process, patented in 1843, made rubber

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864-433: A tracer in hydrologic studies. Differences in the natural abundances can be used in systems where there is sufficient variation in the S of ecosystem components. Rocky Mountain lakes thought to be dominated by atmospheric sources of sulfate have been found to have measurably different S values than lakes believed to be dominated by watershed sources of sulfate. The radioactive S is formed in cosmic ray spallation of

936-441: A wide range of end applications, including in domestic acidic drain cleaners , as an electrolyte in lead-acid batteries , as a dehydrating compound, and in various cleaning agents . Sulfuric acid can be obtained by dissolving sulfur trioxide in water. Although nearly 100% sulfuric acid solutions can be made, the subsequent loss of SO 3 at the boiling point brings the concentration to 98.3% acid. The 98.3% grade, which

1008-401: Is a mineral acid composed of the elements sulfur , oxygen , and hydrogen , with the molecular formula H 2 SO 4 . It is a colorless, odorless, and viscous liquid that is soluble with water. Pure sulfuric acid does not occur naturally due to its strong affinity to water vapor ; it is hygroscopic and readily absorbs water vapor from the air . Concentrated sulfuric acid is

1080-442: Is a common laboratory demonstration. The sugar darkens as carbon is formed, and a rigid column of black, porous carbon called a carbon snake may emerge. Similarly, mixing starch into concentrated sulfuric acid gives elemental carbon and water. The effect of this can also be seen when concentrated sulfuric acid is spilled on paper. Paper is composed of cellulose , a polysaccharide related to starch. The cellulose reacts to give

1152-465: Is a common reagent in organic synthesis . Bromine also oxidizes sulfur to form sulfur dibromide and disulfur dibromide . Sulfur oxidizes cyanide and sulfite to give thiocyanate and thiosulfate , respectively. Sulfur reacts with many metals. Electropositive metals give polysulfide salts. Copper, zinc, and silver are attacked by sulfur; see tarnishing . Although many metal sulfides are known, most are prepared by high temperature reactions of

1224-511: Is a soft, bright-yellow solid that is odorless. It melts at 115.21 °C (239.38 °F), and boils at 444.6 °C (832.3 °F). At 95.2 °C (203.4 °F), below its melting temperature, cyclo-octasulfur begins slowly changing from α-octasulfur to the β- polymorph . The structure of the S 8 ring is virtually unchanged by this phase transition, which affects the intermolecular interactions. Cooling molten sulfur freezes at 119.6 °C (247.3 °F), as it predominantly consists of

1296-484: Is a strong acid: The product of this ionization is HSO − 4 , the bisulfate anion. Bisulfate is a far weaker acid: The product of this second dissociation is SO 2− 4 , the sulfate anion. Concentrated sulfuric acid has a powerful dehydrating property, removing water ( H 2 O ) from other chemical compounds such as table sugar ( sucrose ) and other carbohydrates , to produce carbon , steam , and heat. Dehydration of table sugar (sucrose)

1368-429: Is a very polar liquid, having a dielectric constant of around 100. It has a high electrical conductivity , a consequence of autoprotolysis , i.e. self- protonation  : The equilibrium constant for autoprotolysis (25 °C) is: The corresponding equilibrium constant for water , K w is 10 , a factor of 10 (10 billion) smaller. In spite of the viscosity of the acid, the effective conductivities of

1440-508: Is a very important commodity chemical; a country's sulfuric acid production is a good indicator of its industrial strength. Many methods for its production are known, including the contact process , the wet sulfuric acid process , and the lead chamber process . Sulfuric acid is also a key substance in the chemical industry . It is most commonly used in fertilizer manufacture but is also important in mineral processing , oil refining , wastewater processing , and chemical synthesis . It has

1512-599: Is about 2 g/cm , depending on the allotrope; all of the stable allotropes are excellent electrical insulators. Sulfur sublimes more or less between 20 °C (68 °F) and 50 °C (122 °F). Sulfur is insoluble in water but soluble in carbon disulfide and, to a lesser extent, in other nonpolar organic solvents, such as benzene and toluene . Under normal conditions, sulfur hydrolyzes very slowly to mainly form hydrogen sulfide and sulfuric acid : The reaction involves adsorption of protons onto S 8 clusters, followed by disproportionation into

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1584-451: Is also called brimstone , which means "burning stone". Almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants from natural gas and petroleum . The greatest commercial use of the element is the production of sulfuric acid for sulfate and phosphate fertilizers , and other chemical processes. Sulfur is used in matches , insecticides , and fungicides . Many sulfur compounds are odoriferous, and

1656-499: Is called acid mine drainage (AMD) or acid rock drainage (ARD). The Fe can be further oxidized to Fe : The Fe produced can be precipitated as the hydroxide or hydrous iron oxide : The iron(III) ion ("ferric iron") can also oxidize pyrite: When iron(III) oxidation of pyrite occurs, the process can become rapid. pH values below zero have been measured in ARD produced by this process. ARD can also produce sulfuric acid at

1728-417: Is explained by its production in the so-called alpha-process (one of the main classes of nuclear fusion reactions) in exploding stars. Other stable sulfur isotopes are produced in the bypass processes related with Ar, and their composition depends on a type of a stellar explosion. For example, proportionally more S comes from novae than from supernovae . On the planet Earth the sulfur isotopic composition

1800-402: Is formed by atmospheric oxidation of sulfur dioxide in the presence of water – i.e. oxidation of sulfurous acid . When sulfur-containing fuels such as coal or oil are burned, sulfur dioxide is the main byproduct (besides the chief products carbon oxides and water). Sulfuric acid is formed naturally by the oxidation of sulfide minerals, such as pyrite : The resulting highly acidic water

1872-464: Is higher than the melting point of sulfur. Native sulfur is synthesized by anaerobic bacteria acting on sulfate minerals such as gypsum in salt domes . Significant deposits in salt domes occur along the coast of the Gulf of Mexico , and in evaporites in eastern Europe and western Asia. Native sulfur may be produced by geological processes alone. Fossil-based sulfur deposits from salt domes were once

1944-573: Is mildly acidic: Hydrogen sulfide gas and the hydrosulfide anion are extremely toxic to mammals, due to their inhibition of the oxygen-carrying capacity of hemoglobin and certain cytochromes in a manner analogous to cyanide and azide (see below, under precautions ). The two principal sulfur oxides are obtained by burning sulfur: Many other sulfur oxides are observed including the sulfur-rich oxides include sulfur monoxide , disulfur monoxide , disulfur dioxides, and higher oxides containing peroxo groups. Sulfur reacts with fluorine to give

2016-452: Is more stable in storage, is the usual form of what is described as "concentrated sulfuric acid". Other concentrations are used for different purposes. Some common concentrations are: "Chamber acid" and "tower acid" were the two concentrations of sulfuric acid produced by the lead chamber process , chamber acid being the acid produced in the lead chamber itself (<70% to avoid contamination with nitrosylsulfuric acid ) and tower acid being

2088-399: Is produced by rapid cooling of molten sulfur—for example, by pouring it into cold water. X-ray crystallography studies show that the amorphous form may have a helical structure with eight atoms per turn. The long coiled polymeric molecules make the brownish substance elastic , and in bulk it has the feel of crude rubber. This form is metastable at room temperature and gradually reverts to

2160-557: Is the 10th most common element in the universe . Sulfur, usually as sulfide, is present in many types of meteorites . Ordinary chondrites contain on average 2.1% sulfur, and carbonaceous chondrites may contain as much as 6.6%. It is normally present as troilite (FeS), but there are exceptions, with carbonaceous chondrites containing free sulfur, sulfates and other sulfur compounds. The distinctive colors of Jupiter 's volcanic moon Io are attributed to various forms of molten, solid, and gaseous sulfur. In July 2024, elemental sulfur

2232-408: Is used as a reagent to make the polymer rayon and many organosulfur compounds. Unlike carbon monoxide , carbon monosulfide is stable only as an extremely dilute gas, found between solar systems. Organosulfur compounds are responsible for some of the unpleasant odors of decaying organic matter. They are widely known as the odorant in domestic natural gas, garlic odor, and skunk spray, as well as

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2304-466: The H 3 SO + 4 and HSO − 4 ions are high due to an intramolecular proton-switch mechanism (analogous to the Grotthuss mechanism in water), making sulfuric acid a good conductor of electricity. It is also an excellent solvent for many reactions. The hydration reaction of sulfuric acid is highly exothermic , dilution. As indicated by its acid dissociation constant , sulfuric acid

2376-490: The Hershey-Chase experiment . Because of the weak beta activity of S, its compounds are relatively safe as long as they are not ingested or absorbed by the body. S is created inside massive stars, at a depth where the temperature exceeds 2.5×10  K, by the fusion of one nucleus of silicon plus one nucleus of helium. As this nuclear reaction is part of the alpha process that produces elements in abundance, sulfur

2448-549: The Nama uprising of 1903–07 the hot spring was used by German military forces as a base camp . In 1915, the area was also used as a base by South African troops who were recovering from wounds during the South West Africa Campaign . In 1962, the spring was leased to a local entrepreneur and were subsequently proclaimed a national monument in 1964. In 1969, the springs became a conservation area and on 16 March 1971,

2520-408: The noble gases . Sulfur polycations, S 2+ 8 , S 2+ 4 and S 2+ 16 are produced when sulfur is reacted with oxidizing agents in a strongly acidic solution. The colored solutions produced by dissolving sulfur in oleum were first reported as early as 1804 by C. F. Bucholz, but the cause of the color and the structure of the polycations involved was only determined in

2592-448: The stratosphere , the atmosphere's second layer that is generally between 10 and 50 km above Earth's surface, sulfuric acid is formed by the oxidation of volcanic sulfur dioxide by the hydroxyl radical : Because sulfuric acid reaches supersaturation in the stratosphere, it can nucleate aerosol particles and provide a surface for aerosol growth via condensation and coagulation with other water-sulfuric acid aerosols. This results in

2664-418: The stratospheric aerosol layer . The permanent Venusian clouds produce a concentrated acid rain, as the clouds in the atmosphere of Earth produce water rain. Jupiter 's moon Europa is also thought to have an atmosphere containing sulfuric acid hydrates. Sulfuric acid is produced from sulfur , oxygen and water via the conventional contact process (DCDA) or the wet sulfuric acid process (WSA). In

2736-473: The sulfate minerals , such as gypsum (calcium sulfate), alunite (potassium aluminium sulfate), and barite (barium sulfate). On Earth, just as upon Jupiter's moon Io, elemental sulfur occurs naturally in volcanic emissions, including emissions from hydrothermal vents . The main industrial source of sulfur has become petroleum and natural gas . Common oxidation states of sulfur range from −2 to +6. Sulfur forms stable compounds with all elements except

2808-487: The "science of chemicals" ( Sanskrit : रसशास्त्र , romanized :  rasaśāstra ), wrote extensively about the use of sulfur in alchemical operations with mercury, from the eighth century AD onwards. In the rasaśāstra tradition, sulfur is called "the smelly" ( गन्धक , gandhaka ). Sulfuric acid Sulfuric acid ( American spelling and the preferred IUPAC name ) or sulphuric acid ( Commonwealth spelling ), known in antiquity as oil of vitriol ,

2880-409: The (among others) protein keratin , found in outer skin, hair, and feathers. Sulfur is one of the core chemical elements needed for biochemical functioning and is an elemental macronutrient for all living organisms. Sulfur forms several polyatomic molecules. The best-known allotrope is octasulfur , cyclo-S 8 . The point group of cyclo-S 8 is D 4d and its dipole moment is 0 D. Octasulfur

2952-414: The 2010s, it was thought that sulfate reduction could fractionate sulfur isotopes up to 46 permil and fractionation larger than 46 permil recorded in sediments must be due to disproportionation of sulfur compounds in the sediment. This view has changed since the 2010s as experiments showed that sulfate-reducing bacteria can fractionate to 66 permil. As substrates for disproportionation are limited by

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3024-530: The 3rd century, the Chinese had discovered that sulfur could be extracted from pyrite . Chinese Daoists were interested in sulfur's flammability and its reactivity with certain metals, yet its earliest practical uses were found in traditional Chinese medicine . The Wujing Zongyao of 1044 AD described various formulas for Chinese black powder , which is a mixture of potassium nitrate ( KNO 3 ), charcoal , and sulfur. Indian alchemists, practitioners of

3096-434: The acid is generally avoided since the heat released may boil the solution, spraying droplets of hot acid during the process. Upon contact with body tissue, sulfuric acid can cause severe acidic chemical burns and secondary thermal burns due to dehydration. Dilute sulfuric acid is substantially less hazardous without the oxidative and dehydrating properties; though, it is handled with care for its acidity. Sulfuric acid

3168-466: The acid recovered from the bottom of the Glover tower. They are now obsolete as commercial concentrations of sulfuric acid, although they may be prepared in the laboratory from concentrated sulfuric acid if needed. In particular, "10 M" sulfuric acid (the modern equivalent of chamber acid, used in many titrations ), is prepared by slowly adding 98% sulfuric acid to an equal volume of water, with good stirring:

3240-494: The activity of sulfate-reducing bacteria in the time of formation of the sample, or suggest the main sources of sulfur in ecosystems. However, there are ongoing discussions over the real reason for the δ S shifts, biological activity or postdeposit alteration. For example, when sulfide minerals are precipitated, isotopic equilibration among solids and liquid may cause small differences in the δ S values of co-genetic minerals. The differences between minerals can be used to estimate

3312-736: The addition of state land west of the canyon. Significant renovations to the Ai-Ais camp were carried out in 1987–88. An international treaty , signed in 2003, incorporated the vast area around the ǀAi-ǀAis Hot Springs and Richtersveld National Park in South Africa , resulting in the establishment of the ǀAi-ǀAis/Richtersveld Transfrontier Park . The springs are a popular holiday destination for Namibian, South African and international holiday-makers. The thermal waters are rich in sulphur , chloride and fluoride , and are reputedly good for anyone suffering from rheumatism . The resort waters are also home to

3384-436: The atmospheric Ar . This fact may be used to verify the presence of recent (up to 1 year) atmospheric sediments in various materials. This isotope may be obtained artificially by different ways. In practice, the reaction Cl + n → S + p is used by irradiating potassium chloride with neutrons. The isotope S is used in various sulfur-containing compounds as a radioactive tracer for many biological studies, for example,

3456-648: The basis for commercial production in the United States, Russia, Turkmenistan, and Ukraine. Such sources have become of secondary commercial importance, and most are no longer worked but commercial production is still carried out in the Osiek mine in Poland. Common naturally occurring sulfur compounds include the sulfide minerals , such as pyrite (iron sulfide), cinnabar (mercury sulfide), galena (lead sulfide), sphalerite (zinc sulfide), and stibnite (antimony sulfide); and

3528-413: The camp was officially opened. The thermal water has an average temperature of about 60 °C. The water is piped to a series of indoor pools and jacuzzis. Severe floods in 1972, 1974 and 1988 caused the camp to temporarily close. With the exception of one building—which was situated on higher ground—the 1972 flood totally destroyed the camp. The Fish River Canyon Conservation area was enlarged in 1987 by

3600-530: The chemical formula S 8 . Elemental sulfur is a bright yellow, crystalline solid at room temperature . Sulfur is the tenth most abundant element by mass in the universe and the fifth most common on Earth. Though sometimes found in pure, native form, sulfur on Earth usually occurs as sulfide and sulfate minerals . Being abundant in native form, sulfur was known in ancient times, being mentioned for its uses in ancient India , ancient Greece , China , and ancient Egypt . Historically and in literature sulfur

3672-501: The composition of reaction products. While reaction between sulfur and oxygen under normal conditions gives sulfur dioxide (oxidation state +4), formation of sulfur trioxide (oxidation state +6) requires a temperature of 400–600 °C (750–1,100 °F) and presence of a catalyst. In reactions with elements of lesser electronegativity , it reacts as an oxidant and forms sulfides, where it has oxidation state −2. Sulfur reacts with nearly all other elements except noble gases, even with

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3744-837: The conversion of H 2 SO 4 to [H 3 SO 4 ] by the HF/ SbF 5 system. Even dilute sulfuric acid reacts with many metals via a single displacement reaction, like other typical acids , producing hydrogen gas and salts (the metal sulfate). It attacks reactive metals (metals at positions above copper in the reactivity series ) such as iron , aluminium , zinc , manganese , magnesium , and nickel . Concentrated sulfuric acid can serve as an oxidizing agent , releasing sulfur dioxide: Lead and tungsten , however, are resistant to sulfuric acid. Hot concentrated sulfuric acid oxidizes carbon (as bituminous coal ) and sulfur : Benzene and many derivatives undergo electrophilic aromatic substitution with sulfuric acid to give

3816-412: The corresponding sulfonic acids : Sulfuric acid can be used to produce hydrogen from water : The compounds of sulfur and iodine are recovered and reused, hence the process is called the sulfur–iodine cycle . This process is endothermic and must occur at high temperatures, so energy in the form of heat has to be supplied. The sulfur–iodine cycle has been proposed as a way to supply hydrogen for

3888-606: The corresponding sulfate or bisulfate. Sulfuric acid reacts with sodium chloride , and gives hydrogen chloride gas and sodium bisulfate : Aluminium sulfate , also known as paper maker's alum, is made by treating bauxite with sulfuric acid: Sulfuric acid can also be used to displace weaker acids from their salts. Reaction with sodium acetate , for example, displaces acetic acid , CH 3 COOH , and forms sodium bisulfate : Similarly, treating potassium nitrate with sulfuric acid produces nitric acid . When combined with nitric acid , sulfuric acid acts both as an acid and

3960-451: The crystalline molecular allotrope, which is no longer elastic. This process happens over a matter of hours to days, but can be rapidly catalyzed. Sulfur has 23 known isotopes , four of which are stable: S ( 94.99% ± 0.26% ), S ( 0.75% ± 0.02% ), S ( 4.25% ± 0.24% ), and S ( 0.01% ± 0.01% ). Other than S, with a half-life of 87 days, the radioactive isotopes of sulfur have half-lives less than 3 hours. The preponderance of S

4032-464: The elements. Geoscientists also study the isotopes of metal sulfides in rocks and sediment to study environmental conditions in the Earth's past. Some of the main classes of sulfur-containing organic compounds include the following: Compounds with carbon–sulfur multiple bonds are uncommon, an exception being carbon disulfide , a volatile colorless liquid that is structurally similar to carbon dioxide. It

4104-406: The highly reactive sulfur tetrafluoride and the highly inert sulfur hexafluoride . Whereas fluorine gives S(IV) and S(VI) compounds, chlorine gives S(II) and S(I) derivatives. Thus, sulfur dichloride , disulfur dichloride , and higher chlorosulfanes arise from the chlorination of sulfur. Sulfuryl chloride and chlorosulfuric acid are derivatives of sulfuric acid; thionyl chloride (SOCl 2 )

4176-484: The largest documented single crystal measuring 22 cm × 16 cm × 11 cm (8.7 in × 6.3 in × 4.3 in). Historically, Sicily was a major source of sulfur in the Industrial Revolution . Lakes of molten sulfur up to about 200 m (660 ft) in diameter have been found on the sea floor, associated with submarine volcanoes , at depths where the boiling point of water

4248-415: The late 1960s. S 2+ 8 is deep blue, S 2+ 4 is yellow and S 2+ 16 is red. Reduction of sulfur gives various polysulfides with the formula S x , many of which have been obtained in crystalline form. Illustrative is the production of sodium tetrasulfide : Some of these dianions dissociate to give radical anions , such as S − 3 gives the blue color of

4320-573: The notoriously unreactive metal iridium (yielding iridium disulfide ). Some of those reactions require elevated temperatures. Sulfur forms over 30 solid allotropes , more than any other element. Besides S 8 , several other rings are known. Removing one atom from the crown gives S 7 , which is of a deeper yellow than S 8 . HPLC analysis of "elemental sulfur" reveals an equilibrium mixture of mainly S 8 , but with S 7 and small amounts of S 6 . Larger rings have been prepared, including S 12 and S 18 . Amorphous or "plastic" sulfur

4392-407: The product of sulfate reduction , the isotopic effect of disproportionation should be less than 16 permil in most sedimentary settings. In forest ecosystems, sulfate is derived mostly from the atmosphere; weathering of ore minerals and evaporites contribute some sulfur. Sulfur with a distinctive isotopic composition has been used to identify pollution sources, and enriched sulfur has been added as

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4464-420: The reaction products. The second, fourth and sixth ionization energies of sulfur are 2252 kJ/mol, 4556 kJ/mol and 8495.8 kJ/mol, respectively. The composition of reaction products of sulfur with oxidants (and its oxidation state) depends on whether releasing of reaction energy overcomes these thresholds. Applying catalysts and/or supply of external energy may vary sulfur's oxidation state and

4536-509: The rock lapis lazuli . This reaction highlights a distinctive property of sulfur: its ability to catenate (bind to itself by formation of chains). Protonation of these polysulfide anions produces the polysulfanes , H 2 S x , where x = 2, 3, and 4. Ultimately, reduction of sulfur produces sulfide salts: The interconversion of these species is exploited in the sodium–sulfur battery . Treatment of sulfur with hydrogen gives hydrogen sulfide . When dissolved in water, hydrogen sulfide

4608-719: The smells of odorized natural gas, skunk scent, bad breath , grapefruit , and garlic are due to organosulfur compounds. Hydrogen sulfide gives the characteristic odor to rotting eggs and other biological processes. Sulfur is an essential element for all life, almost always in the form of organosulfur compounds or metal sulfides. Amino acids (two proteinogenic : cysteine and methionine , and many other non-coded : cystine , taurine , etc.) and two vitamins ( biotin and thiamine ) are organosulfur compounds crucial for life. Many cofactors also contain sulfur, including glutathione , and iron–sulfur proteins . Disulfides , S–S bonds, confer mechanical strength and insolubility of

4680-458: The solid state, sulfuric acid is a molecular solid that forms monoclinic crystals with nearly trigonal lattice parameters. The structure consists of layers parallel to the (010) plane, in which each molecule is connected by hydrogen bonds to two others. Hydrates H 2 SO 4 · n H 2 O are known for n = 1, 2, 3, 4, 6.5, and 8, although most intermediate hydrates are stable against disproportionation . Anhydrous H 2 SO 4

4752-465: The temperature of equilibration. The δ C and δ S of coexisting carbonate minerals and sulfides can be used to determine the pH and oxygen fugacity of the ore-bearing fluid during ore formation. Scientists measure the sulfur isotopes of minerals in rocks and sediments to study the redox conditions in past oceans. Sulfate-reducing bacteria in marine sediment fractionate sulfur isotopes as they take in sulfate and produce sulfide . Prior to

4824-449: The temperature of the mixture can rise to 80 °C (176 °F) or higher. Sulfuric acid contains not only H 2 SO 4 molecules, but is actually an equilibrium of many other chemical species, as it is shown in the table below. Sulfuric acid is a colorless oily liquid, and has a vapor pressure of <0.001 mmHg at 25 °C and 1 mmHg at 145.8 °C, and 98% sulfuric acid has a vapor pressure of <1 mmHg at 40 °C. In

4896-505: The term " fire-and-brimstone " sermons , in which listeners are reminded of the fate of eternal damnation that await the unbelieving and unrepentant. It is from this part of the Bible that Hell is implied to "smell of sulfur" (likely due to its association with volcanic activity). According to the Ebers Papyrus , a sulfur ointment was used in ancient Egypt to treat granular eyelids. Sulfur

4968-419: The β-S 8 molecules. Between its melting and boiling temperatures, octasulfur changes its allotrope again, turning from β-octasulfur to γ-sulfur, again accompanied by a lower density but increased viscosity due to the formation of polymers . At higher temperatures, the viscosity decreases as depolymerization occurs. Molten sulfur assumes a dark red color above 200 °C (392 °F). The density of sulfur

5040-615: Was accidentally discovered to exist on Mars after the Curiosity rover drove over and crushed a rock, revealing sulfur crystals inside it. Sulfur is the fifth most common element by mass in the Earth. Elemental sulfur can be found near hot springs and volcanic regions in many parts of the world, especially along the Pacific Ring of Fire ; such volcanic deposits are mined in Indonesia, Chile, and Japan. These deposits are polycrystalline, with

5112-549: Was determined by the Sun. Though it was assumed that the distribution of different sulfur isotopes would be more or less equal, it has been found that proportions of the two most abundant sulfur isotopes S and S varies in different samples. Assaying of the isotope ratio ( δ S ) in the samples suggests their chemical history, and with support of other methods, it allows to age-date the samples, estimate temperature of equilibrium between ore and water, determine pH and oxygen fugacity , identify

5184-622: Was used for fumigation in preclassical Greece ; this is mentioned in the Odyssey . Pliny the Elder discusses sulfur in book 35 of his Natural History , saying that its best-known source is the island of Melos . He mentions its use for fumigation, medicine, and bleaching cloth. A natural form of sulfur known as shiliuhuang ( 石硫黄 ) was known in China since the 6th century BC and found in Hanzhong . By

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