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H3PO4
Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, which is a colourless, odourless, and non- volatile syrupy liquid. It is a major industrial chemical, being a component of many fertilizers. The compound is an acid. Removal of all three ions gives the phosphate ion . Removal of one or two protons gives dihydrogen phosphate ion , and the hydrogen phosphate ion , respectively. Phosphoric acid forms esters, called organophosphates. The name "orthophosphoric acid" can be used to distinguish this specific acid from other "phosphoric acids", such as pyrophosphoric acid. Nevertheless, the term "phosphoric acid" often means this specific compound; and that is the current IUPAC nomenclature. Production Phosphoric acid is produced industrially by one of two routes, wet processes and dry. We ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxomonophosphoric Acid
Peroxymonophosphoric acid () is an oxyacid of phosphorus. It is a colorless viscous oil. Its salts are called peroxymonophosphates. Another peroxyphosphoric acid is peroxydiphosphoric acid, . Preparation Peroxyphosphoric acids were first synthesized and characterized in 1910 by Julius Schmidlin and Paul Massini via the reaction between phosphorus pentoxide and highly-concentrated aqueous solution of hydrogen peroxide. However, this reaction proceeds very vigorously and is difficult to control. Aside from phosphorus pentoxide, syntheses from metaphosphoric acid and diphosphoric acid were also reported. : P2O5 + 2H2O2 + H2O -> 2H3PO5 : H4P4O12 + 4H2O2 -> 4H3PO5 : H4P2O7 + H2O2 -> H3PO5 + H3PO4 A less vigorous method of preparing peroxyphosphoric acid by introducing the inert solvent acetonitrile was described by Gerrit Toennies in 1937. This method was shown to be unsuitable in diethyl ether or isoamyl alcohol. Contemporary methods Peroxyphosphoric acid is usually produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrophosphoric Acid
Pyrophosphoric acid, also known as diphosphoric acid, is the inorganic compound with the formula H4P2O7 or, more descriptively, HO)2P(O)sub>2O. Colorless and odorless, it is soluble in water, diethyl ether, and ethyl alcohol. The anhydrous acid crystallizes in two polymorphs, which melt at 54.3 and 71.5 °C. The compound is a component of polyphosphoric acid, an important source of phosphoric acid. Anions, salts, and esters of pyrophosphoric acid are called pyrophosphates. Preparation It can be prepared by reaction of phosphoric acid with phosphoryl chloride: : → It can also be prepared by ion exchange from sodium pyrophosphate or by treating lead pyrophosphate with hydrogen sulfide. Reactions Pyrophosphoric acid is a tetraprotic acid, with four distinct pKa's: :, pKa = 0.85 :, pKa = 1.96 :, pKa = 6.60 :, pKa = 9.41 The pKa's occur in two distinct ranges because deprotonations occur on separate phosphate groups. For comparison with the pKa's for phosphoric acid are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorous Acid
Phosphorous acid (or phosphonic acid (singular)) is the compound described by the formula H3PO3. This acid is diprotic (readily ionizes two protons), not triprotic as might be suggested by this formula. Phosphorous acid is an intermediate in the preparation of other phosphorus compounds. Organic derivatives of phosphorous acid, compounds with the formula RPO3H2, are called phosphonic acids. Nomenclature and tautomerism H3PO3 is more clearly described with the structural formula HPO(OH)2. In the solid state, has tetrahedral geometry about the central phosphorus atom, with a P–H bond of 132 pm, one P=O double bond of 148 pm and two longer P–O(H) single bonds of 154 pm. This species exists in equilibrium with an extremely minor tautomer . IUPAC recommends that the latter be called phosphorous acid, whereas the dihydroxy form is called phosphonic acid.. Only the reduced phosphorus compounds are spelled with an "ous" ending. Other important oxyacids of pho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrophosphoric Acid
Pyrophosphoric acid, also known as diphosphoric acid, is the inorganic compound with the formula H4P2O7 or, more descriptively, HO)2P(O)sub>2O. Colorless and odorless, it is soluble in water, diethyl ether, and ethyl alcohol. The anhydrous acid crystallizes in two polymorphs, which melt at 54.3 and 71.5 °C. The compound is a component of polyphosphoric acid, an important source of phosphoric acid. Anions, salts, and esters of pyrophosphoric acid are called pyrophosphates. Preparation It can be prepared by reaction of phosphoric acid with phosphoryl chloride: : → It can also be prepared by ion exchange from sodium pyrophosphate or by treating lead pyrophosphate with hydrogen sulfide. Reactions Pyrophosphoric acid is a tetraprotic acid, with four distinct pKa's: :, pKa = 0.85 :, pKa = 1.96 :, pKa = 6.60 :, pKa = 9.41 The pKa's occur in two distinct ranges because deprotonations occur on separate phosphate groups. For comparison with the pKa's for phosphoric acid are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxodiphosphoric Acid
Peroxydiphosphoric acid (H4P2O8) is an oxyacid of phosphorus. Its salts are known as peroxydiphosphates. It is one of two peroxyphosphoric acids, along with peroxymonophosphoric acid. History Both peroxyphosphoric acids were first synthesized and characterized in 1910 by Julius Schmidlin and Paul Massini, where peroxydiphosphoric acid was obtained in poor yields from the reaction between diphosphoric acid and highly-concentrated hydrogen peroxide. : H4P2O7 + H2O2 -> H4P2O8 + H2O Preparation Peroxydiphosphoric acid can be prepared by the reaction between phosphoric acid and fluorine, with peroxymonophosphoric acid being a by-product. : 2H3PO4 + F2 -> H4P2O8 + 2HF The compound is not commercially available and must be prepared as needed. Peroxodiphosphates can be obtained by electrolysis of phosphate solutions. Properties Peroxydiphosphoric acid is a tetraprotic acid, with acid dissociation constants given by pKa1 ≈ −0.3, pKa2 ≈ 0.5, pKa3 = 5.2 and pKa4 = 7.6. In a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydrogen Phosphate
Dihydrogen phosphate or dihydrogenphosphate ion is an inorganic ion with the formula −. Phosphates occur widely in natural systems. These sodium phosphates are artificially used in food processing and packaging as emulsifying agents, neutralizing agents, surface-activating agents, and leavening agents providing humans with benefits. Emulsifying agents prevent separation of two ingredients in processed foods that would separate under natural conditions while neutralizing agents make processed foods taste fresher longer and lead to an increased shelf-life of these foods. Surface-activating agents prevent surface-tension formation on liquid-containing processed foods and finally, leavening agents are used in processed foods to aid in the expansion of yeast in baked goods. Dihydrogen phosphate is employed in the production of pharmaceuticals furthering their importance to medical practitioners of gastroenterology and humans in general. In this medical discipline, sodium phosphates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 the elements sulfur, oxygen and hydrogen, with the molecular formula . It is a colorless, odorless and viscous liquid that is miscible with water. Pure sulfuric acid does not exist naturally on Earth due to its strong affinity to water vapor; it is hygroscopic and readily absorbs water vapor from the air. Concentrated sulfuric acid is highly corrosive towards other materials, from rocks to metals, since it is an oxidant with powerful dehydrating properties. 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 the acid should not be performed since the heat released may boi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethanol
Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an Alcohol (chemistry), alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a hydroxyl group). Ethanol is a Volatility (chemistry), volatile, Combustibility and flammability, flammable, colorless liquid with a characteristic wine-like odor and pungent taste. It is a psychoactive recreational drug, the active ingredient in alcoholic drinks. Ethanol is naturally produced by the fermentation process of Carbohydrate, sugars by yeasts or via Petrochemistry, petrochemical processes such as ethylene hydration. It has medical applications as an antiseptic and disinfectant. It is used as a chemical solvent and in the Chemical synthesis, synthesis of organic compounds, and as a Alcohol fuel, fuel source. Ethanol also can be dehydrated to make ethylene, an important chemical feedstock. As of 2006, world produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organophosphate
In organic chemistry, organophosphates (also known as phosphate esters, or OPEs) are a class of organophosphorus compounds with the general structure , a central phosphate molecule with alkyl or aromatic substituents. They can be considered as esters of phosphoric acid. Like most functional groups, organophosphates occur in a diverse range of forms, with important examples including key biomolecules such as DNA, RNA and ATP, as well as many insecticides, herbicides, nerve agents and flame retardants. OPEs have been widely used in various products as flame retardants, plasticizers, and performance additives to engine oil. The popularity of OPEs as flame retardants came as a substitution for the highly regulated brominated flame retardants. The low cost of production and compatibility to diverse polymers made OPEs to be widely used in industry including textile, furniture, electronics as plasticizers and flame retardants. These compounds are added to the final product physica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'', also widely referred to as ''Science Magazine'', is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphoric Acids And Phosphates
A phosphoric acid, in the general sense, is a phosphorus oxoacid in which each phosphorus (P) atom is in the oxidation state +5, and is bonded to four oxygen (O) atoms, one of them through a double bond, arranged as the corners of a tetrahedron. Two or more of these tetrahedra may be connected by shared single-bonded oxygens, forming linear or branched chains, cycles, or more complex structures. The single-bonded oxygen atoms that are not shared are completed with acidic hydrogen atoms. The general formula of a phosphoric acid is , where ''n'' is the number of phosphorus atoms and ''x'' is the number of fundamental cycles in the molecule's structure, between 0 and (''n''+2)/2. Removal of protons () from ''k'' hydroxyl groups –OH leaves anions generically called phosphates (if ''k'' = ''n''−2''x''+2) or hydrogen phosphates (if ''k'' is between 1 and ''n''−2''x''+1), with general formula ''n''−2''x''+2−''k''P''n''O3''n''+1−''x''sup>''k''−. The fully dissociated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorapatite
Fluorapatite, often with the alternate spelling of fluoroapatite, is a phosphate mineral with the formula Ca5(PO4)3F (calcium fluorophosphate). Fluorapatite is a hard crystalline solid. Although samples can have various color (green, brown, blue, yellow, violet, or colorless), the pure mineral is colorless, as expected for a material lacking transition metals. Along with hydroxylapatite, it can be a component of tooth enamel, but for industrial use both minerals are mined in the form of phosphate rock, whose usual mineral composition is primarily fluorapatite but often with significant amounts of the other. Fluorapatite crystallizes in a hexagonal crystal system. It is often combined as a solid solution with hydroxylapatite (Ca5(PO4)3OH or Ca10(PO4)6(OH)2) in biological matrices. Chlorapatite (Ca5(PO4)3Cl) is another related structure. Industrially, the mineral is an important source of both phosphoric and hydrofluoric acids. Fluorapatite as a mineral is the most common p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
