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Silicon Tetrafluoride
Silicon tetrafluoride or tetrafluorosilane is a chemical compound with the formula Si F4. This colorless gas is notable for having a narrow liquid range: its boiling point is only 4 °C above its melting point. It was first prepared in 1771 by Carl Wilhelm Scheele by dissolving silica in hydrofluoric acid, and later synthesized by John Davy in 1812. It is a tetrahedral molecule and is corrosive. Occurrence Volcanic plumes contain significant amounts of silicon tetrafluoride. Production can reach several tonnes per day. Some amounts are also emitted from spontaneous coal fires.Kruszewski, Ł., Fabiańska, M.J., Ciesielczuk, J., Segit, T., Orłowski, R., Motyliński, R., Moszumańska, I., Kusy, D. 2018 – First multi-tool exploration of a gas-condensate-pyrolysate system from the environment of burning coal mine heaps: An in situ FTIR and laboratory GC and PXRD study based on Upper Silesian materials. Science of the Total Environment, 640-641, 1044-1071; DOI: 10.1016/j.sci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debye
The debye ( , ; symbol: D) is a CGS unit (a non- SI metric unit) of electric dipole momentTwo equal and opposite charges separated by some distance constitute an electric dipole. This dipole possesses an electric dipole moment whose value is given as charge times length of separation. The dipole itself is a vector whose direction coincides with the position vector of the positive charge with respect to the negative charge: : p = ''q''r. named in honour of the physicist Peter J. W. Debye. It is defined as statcoulomb-centimetres.The statcoulomb is also known as the franklin or electrostatic unit of charge. : 1 statC = 1 Fr = 1 esu = 1 cm3/2⋅g1/2⋅s−1. Historically the debye was defined as the dipole moment resulting from two charges of opposite sign but an equal magnitude of 10−10 statcoulomb10−10 statcoulomb corresponds to approximately 0.2083 units of elementary charge. (generally called e.s.u. (electrostatic unit) in ol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphate
Phosphates are the naturally occurring form of the element phosphorus. In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid, phosphoric acid . The phosphate or orthophosphate ion is derived from phosphoric acid by the removal of three protons . Removal of one proton gives the dihydrogen phosphate ion while removal of two protons gives the hydrogen phosphate ion . These names are also used for salts of those anions, such as ammonium dihydrogen phosphate and trisodium phosphate. File:3-phosphoric-acid-3D-balls.png, Phosphoricacid File:2-dihydrogenphosphate-3D-balls.png, Dihydrogenphosphate File:1-hydrogenphosphate-3D-balls.png, Hydrogenphosphate File:0-phosphate-3D-balls.png, Phosphate or orthophosphate In organic chemistry, phosphate or orthophosphate is an organophosphate, an ester of orthophosphoric acid of the form where one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorosilicic Acid
Hexafluorosilicic acid is an inorganic compound with the chemical formula . Aqueous solutions of hexafluorosilicic acid consist of salts of the cation and hexafluorosilicate anion. These salts and their aqueous solutions are colorless. Hexafluorosilicic acid is produced naturally on a large scale in volcanoes.Palache, C., Berman, H., and Frondel, C. (1951) Dana’s System of Mineralogy, Volume II: Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, etc. John Wiley and Sons, Inc., New York, 7th edition.Anthony, J.W., Bideaux, R.A., Bladh, K.W., and Nichols, M.C. (1997) Handbook of Mineralogy, Volume III: Halides, Hydroxides, Oxides. Mineral Data Publishing, Tucson.Bararite It is manufactured as a coproduct in the production of phosphate fertilizers. The resulting hexafluorosilicic acid is almost exclusively consumed as a precursor to aluminum trifluoride and synthetic cryolite, which are used in aluminium processing. Salts derived f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Synthesis
Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the general subject of organic synthesis, there are many different types of synthetic routes that can be completed including total synthesis, Enantioselective synthesis, stereoselective synthesis, automated synthesis, and many more. Additionally, in understanding organic synthesis it is necessary to be familiar with the methodology, techniques, and applications of the subject. Total synthesis A total synthesis refers to the complete chemical synthesis of molecules from simple, Precursor (chemistry), natural precursors. Total synthesis is accomplished either via a linear or convergent approach. In a Linear synthesis, ''linear'' synthesis—often adequate for simple structures—several steps are performed sequentially until the molecule is com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volatility (chemistry)
In chemistry, volatility is a material quality which describes how readily a substance vaporizes. At a given temperature and pressure, a substance with high volatility is more likely to exist as a vapour, while a substance with low volatility is more likely to be a liquid or solid. Volatility can also describe the tendency of a vapor to condense into a liquid or solid; less volatile substances will more readily condense from a vapor than highly volatile ones. Differences in volatility can be observed by comparing how fast substances within a group evaporate (or sublimate in the case of solids) when exposed to the atmosphere. A highly volatile substance such as rubbing alcohol (isopropyl alcohol) will quickly evaporate, while a substance with low volatility such as vegetable oil will remain condensed. In general, solids are much less volatile than liquids, but there are some exceptions. Solids that sublimate (change directly from solid to vapor) such as dry ice (solid carbon di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Fluoride
Sodium fluoride (NaF) is an inorganic compound with the formula . It is a colorless or white solid that is readily soluble in water. It is used in trace amounts in the fluoridation of drinking water to prevent tooth decay, and in toothpastes and topical pharmaceuticals for the same purpose. In 2022, it was the 221st most commonly prescribed medication in the United States, with more than 1million prescriptions. It is also used in metallurgy and in medical imaging. Uses Dental caries Fluoride salts are often added to municipal drinking water (as well as to certain food products in some countries) for the purpose of maintaining dental health. The fluoride enhances the strength of teeth by the formation of fluorapatite, a naturally occurring component of tooth enamel. Although sodium fluoride is used to fluoridate water and is the standard by which other water-fluoridation compounds are gauged, hexafluorosilicic acid (H2SiF6) and its salt sodium hexafluorosilicate (Na2Si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Hexafluorosilicate
Sodium fluorosilicate is a compound with the chemical formula Na2 iF6 Unlike other sodium salts, it has a low solubility in water. Natural occurrence Sodium hexafluorosilicate occurs naturally as the rare mineral malladrite found within some volcanic fumaroles. Manufacturing Sodium fluorosilicate is made by neutralizing fluorosilicic acid with sodium chloride or sodium sulfate. :H2 iF6+ 2 NaCl → Na2 iF6+ 2 HCl Possible application Sodium fluorosilicate is used in some countries as additives for water fluoridation, opal glass raw material, ore refining, or other fluoride chemical (like sodium fluoride, magnesium silicofluoride, cryolite, aluminum fluoride) production. It is used for extraction of beryllium from beryl Beryl ( ) is a mineral composed of beryllium aluminium Silicate minerals#Cyclosilicates, silicate with the chemical formula Be3Al2(SiO3)6. Well-known varieties of beryl include emerald and Aquamarine (gem), aquamarine. Naturally occurring Hex ..., by ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barium Fluoride
Barium fluoride is an inorganic compound with the formula . It is a colorless solid that occurs in nature as the rare mineral frankdicksonite. Under standard conditions it adopts the fluorite structure and at high pressure the structure. Like , it is resilient to and insoluble in water. Above ca. 500 °C, is corroded by moisture, but in dry environments it can be used up to 800 °C. Prolonged exposure to moisture degrades transmission in the vacuum UV range. It is less resistant to water than calcium fluoride, but it is the most resistant of all the optical fluorides to high-energy radiation, though its far ultraviolet transmittance is lower than that of the other fluorides. It is quite hard, very sensitive to thermal shock and fractures quite easily. Optical properties Barium fluoride is transparent from the ultraviolet to the infrared, from 150 to 200 nm to 11–11.5 μm. It is used in windows for infrared spectroscopy, in particular in the field of fuel oi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barium Hexafluorosilicate
Barium hexafluorosilicate is an inorganic chemical compound with the chemical formula . Synthesis As a salt that is poorly soluble in water, barium hexafluorosilicate precipitates from solutions that contain barium ions (e.g. barium chloride as well as hexafluorosilicate ions (e.g. hexafluorosilicic acid). : Uses The compound is used as a chemical reagent in experimental applications. In various chemical reactions and processes, the compound acts as a source of barium and hexafluorosilicate ions. It was also used as an insecticide Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. The major use of insecticides is in agriculture, but they are also used in home and garden settings, i .... References {{fluorine compounds Barium compounds Hexafluorosilicates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphate Mineral
Phosphate minerals are minerals that contain the tetrahedrally coordinated phosphate () anion, sometimes with arsenate () and vanadate () substitutions, along with chloride (Cl−), fluoride (F−), and hydroxide (OH−) anions, that also fit into the crystal structure. The phosphate class of minerals is a large and diverse group, however, only a few species are relatively common. Applications Phosphate rock has high concentration of phosphate minerals, most commonly from the apatite group of minerals. It is the major resource mined to produce phosphate fertilizers for the agricultural industry. Phosphate is also used in animal feed supplements, food preservatives, anti-corrosion agents, cosmetics, fungicides, ceramics, water treatment and metallurgy. The production of fertilizer is the largest source responsible for minerals mined for their phosphate content. Phosphate minerals are often used to control rust, and to prevent corrosion on ferrous materials applied with ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicate
A silicate is any member of a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula , where . The family includes orthosilicate (), metasilicate (), and pyrosilicate (, ). The name is also used for any salt of such anions, such as sodium metasilicate; or any ester containing the corresponding chemical group, such as tetramethyl orthosilicate. The name "silicate" is sometimes extended to any anions containing silicon, even if they do not fit the general formula or contain other atoms besides oxygen; such as hexafluorosilicate . Most commonly, silicates are encountered as silicate minerals. For diverse manufacturing, technological, and artistic needs, silicates are versatile materials, both natural (such as granite, gravel, and garnet) and artificial (such as Portland cement, ceramics, glass, and waterglass). Structural principles In most silicates, a silicon atom occupies the center of an idealized tetrahedron whose cor ... [...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, especially in individuals who use fluoridated toothpaste, 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 hydr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
