32-469: E501 may refer to: E number 501 , a food additive E501 series , electric multiple unit operating in Japan [REDACTED] Topics referred to by 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
64-434: 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
96-610: 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
128-408: 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
160-411: 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
192-470: A derogatory term for artificial food additives. For example, in the UK, food companies are required to include the 'E Number(s)' in the ingredients that are added as part of the manufacturing process. Many components of naturally occurring healthy foods and vitamins have assigned E numbers (and the number is a synonym for the chemical component), e.g. vitamin C ( E300 ) and lycopene ( E160d ), found in carrots. At
224-566: A single unified list for food additives was first agreed upon in 1962 with food colouring . In 1964, the directives for preservatives were added, in 1970 antioxidants were added, in 1974 emulsifiers, stabilisers, thickeners and gelling agents were added as well. The numbering scheme follows that of the International Numbering System (INS) as determined by the Codex Alimentarius committee, though only
256-487: 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
288-766: A subset of the INS additives are approved for use in the European Union as food additives. Outside the European continent plus Russia, E numbers are also encountered on food labelling in other jurisdictions, including the Cooperation Council for the Arab States of the Gulf , South Africa, Australia, New Zealand, Malaysia, Hong Kong, and India. In some European countries, the "E number" is used informally as
320-510: A vapor pressure of <1 mmHg at 40 °C. In 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
352-442: 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
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#1732790852511384-556: 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 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
416-484: 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)
448-429: 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
480-547: 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 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,
512-502: 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
544-402: 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
576-493: Is prepared by slowly adding 98% sulfuric acid to an equal volume of water, with good stirring: 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
608-428: Is substantially less hazardous without the oxidative and dehydrating properties; though, it is handled with care for its acidity. Sulfuric acid 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
640-471: 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
672-642: The European Union (EU) and European Free Trade Association (EFTA). Commonly found on food labels , their safety assessment and approval are the responsibility of the European Food Safety Authority (EFSA). The fact that an additive has an E number implies that its use was at one time permitted in products for sale in the European Single Market ; some of these additives are no longer allowed today. Having
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#1732790852511704-448: 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
736-418: 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
768-552: The E400–499 range) have a variety of purposes. The list shows all components that have an E-number assigned, even those no longer allowed in the EU . Banned in the US and Australia. Sulfuric acid Sulfuric acid ( American spelling and the preferred IUPAC name ) or sulphuric acid ( Commonwealth spelling ), known in antiquity as oil of vitriol , is a mineral acid composed of
800-502: The acid produced in the lead chamber itself (<70% to avoid contamination with nitrosylsulfuric acid ) and tower acid being 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 ),
832-842: 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
864-412: 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
896-606: 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
928-520: 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 a strong oxidant with powerful dehydrating properties, making it highly corrosive towards other materials, from rocks to metals. Phosphorus pentoxide
960-587: The intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=E501&oldid=897071354 " Category : Letter–number combination disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages E number#E500.E2.80.93E599 .28acidity regulators.2C anti-caking agents.29 E numbers , short for Europe numbers, are codes for substances used as food additives , including those found naturally in many foods, such as vitamin C , for use within
992-464: The same time, "E number" is sometimes misunderstood to imply approval for safe consumption. This is not necessarily the case, e.g. Avoparcin ( E715 ) is an antibiotic once used in animal feed, but is no longer permitted in the EU, and has never been permitted for human consumption. Sodium nitrite (E250) is toxic. Sulfuric acid (E513) is caustic. Not all examples of a class fall into the given numeric range; moreover, certain chemicals (particularly in
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1024-445: The subsequent loss of SO 3 at the boiling point brings the concentration to 98.3% acid. The 98.3% grade, which 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
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