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Tetraethyllead
Tetraethyllead (commonly styled tetraethyl lead), abbreviated TEL, is an organolead compound with the formula lead, Pb(ethyl group, C2H5)4. It was widely used as a fuel additive for much of the 20th century, first being mixed with gasoline beginning in the 1920s. This "leaded gasoline" had an increased octane rating that allowed Compression ratio, engine compression to be raised substantially and in turn increased vehicle performance and fuel economy. TEL was first chemical synthesis, synthesized by German chemist Carl Jacob Löwig in 1853. American chemical engineer Thomas Midgley Jr., who was working for the U.S. corporation General Motors, was the first to discover its effectiveness as an Antiknock agent, knock inhibitor on December 9th, 1921, after spending six years attempting to find an antiknock agent, additive that was both highly effective and inexpensive. Of the some 33,000 substances in total screened, lead was found to be the most effective antiknock agent, in that i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead Poisoning
Lead poisoning, also known as plumbism and saturnism, is a type of metal poisoning caused by lead in the body. Symptoms may include abdominal pain, constipation, headaches, irritability, memory problems, infertility, numbness and paresthesia, tingling in the hands and feet. It causes almost 10% of intellectual disability of otherwise unknown cause and can result in behavioral problems. Some of the effects are permanent. In severe cases, anemia, seizures, coma, or death may occur. Exposure to lead can occur by contaminated air, water, dust, food, or consumer products. Lead poisoning poses a significantly increased risk to children and pets as they are far more likely to ingest lead indirectly by chewing on toys or other objects that are coated in lead paint. Additionally, children absorb greater quantities of lead from ingested sources than adults. Exposure at work is a common cause of lead poisoning in adults with certain occupations at particular risk. Diagnosis is typically b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Midgley Jr
Thomas Midgley Jr. (May 18, 1889 – November 2, 1944) was an American mechanical and chemical engineer. He played a major role in developing leaded gasoline (tetraethyl lead) and some of the first chlorofluorocarbons (CFCs), better known in the United States by the brand name Freon; both products were later banned from common use due to their harmful impact on human health and the environment. He was granted more than 100 patents over the course of his career. Midgley contracted polio in 1940 and was left disabled; in 1944, he was found strangled to death by a device he devised to allow him to get out of bed unassisted. It is often reported that he had been accidentally killed by his own invention, but his death was declared by the coroner to be a suicide. While the harmful effects of CFCs were not appreciated until decades after Midgley's death, tetraethyl lead was known to be acutely toxic by those involved in the development of leaded gasoline. This included Midgley ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead
Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to air. Lead has the highest atomic number of any stable nuclide, stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is a relatively unreactive post-transition metal. Its weak metallic character is illustrated by its Amphoterism, amphoteric nature; lead and lead oxides react with acids and base (chemistry), bases, and it tends to form covalent bonds. Lead compounds, Compounds of lead are usually found in the +2 oxidation state rather than the +4 state common with lighter members of the carbon group. Exceptions are mostly limited ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiknock Agent
An antiknock agent (also: knock inhibitor) is a gasoline additive used to reduce engine knocking and increase the fuel's octane rating by raising the temperature and pressure at which auto-ignition occurs. The mixture known as gasoline or petrol, when used in high compression internal combustion engines, has a tendency to knock (also called "pinging" or "pinking") and/or to ignite early before the correctly timed spark occurs (''pre-ignition'', refer to engine knocking). Notable early antiknock agents, especially tetraethyllead, added to gasoline included large amounts of toxic lead. The chemical was responsible for global negative impacts on health, and the phase out of leaded gasoline from the 1970s onward was reported by the United Nations Environmental Programme to be responsible for "$2.4 trillion in annual benefits, 1.2 million fewer premature deaths, higher overall intelligence and 58 million fewer crimes." Some other chemicals used as gasoline additives are thought to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetramethyllead
Tetramethyllead, also called tetra methyllead and lead tetramethyl, is a chemical compound used as an antiknock additive for gasoline. It is a methyl radical synthon. Its use in gasoline is being phased out for environmental considerations. The National Institute for Occupational Safety and Health (NIOSH) in the United States has identified tetramethyllead as a potential workplace hazard. The recommended time-weighted average exposure limit to tetramethyllead is 0.075 milligrams per cubic meter during a 10-hour workday; the OSHA permissible exposure limit is the same value assuming an 8-hour workday. Exposure to tetramethyllead can affect the central nervous system, the kidneys, and the cardiovascular system. Tetramethyllead can be absorbed through inhalation, through eye contact, through skin absorption, and by ingesting the substance. Symptoms of exposure include insomnia, coma, seizure, mania, delirium, loss of appetite, nausea, hypotension, anxiety, restlessness, and n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraethylgermanium
Tetraethylgermanium (IUPAC name: tetraethylgermane), abbreviated TEG, is an organogermanium compound with the formula ( CH3CH2)4 Ge. Tetraethylgermanium is an important chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ... used in vapour deposition of germanium which is in a tetrahedral shape. Synthesis Clemens Winkler first reported the compound in 1887 from diethylzinc and germanium tetrachloride, shortly after germanium was discovered in 1887. References {{Reflist External links * TetraethylgermaniuDatasheet commercial supplier Organogermanium compounds Germanium(IV) compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraethyltin
Tetraethyltin or tetraethyl tin is a chemical compound with the formula , that is, a tin atom attached to four ethyl groups. It is an important example of an organotin compound, often abbreviated as TET. Tetraethyltin is a colourless flammable liquid, soluble in diethyl ether and insoluble in water, that freezes at −112 °C and boils at 181 °C.SAFC corp''tetraethyltin''catalog page. Accessed on 2011-01-18. It is used in the electronics industry. Tetraethyltin can be obtained by reacting ethylmagnesium bromide with tin(IV) chloride:G. J. M. Van Der Kerk and J. G. A. Luijten (1956)"Tetraethyltin" ''Organic Syntheses'', volume 36, page 86; Coll. Vol. 4, p.881 (1963) : The same reaction can be used to obtain tetra-''n''-propyltin and tetra-''n''-butyltin. Tetraethyltin is converted in the body to the more toxic triethylstannylium ions.Jill E. Cremer (1958), "The biochemistry of organotin compounds. The conversion of tetraethyltin into triethyltin in mammals". ''Bioc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraethylmethane
Tetraethylmethane is a branched alkane with 9 carbon atoms. It is a colorless, highly flammable, and volatile liquid at room temperature. It is one of the isomers of nonane. References See also *Neopentane Neopentane, also called 2,2-dimethylpropane, is a double-branched-chain alkane with five carbon atoms. Neopentane is a flammable gas at room temperature and pressure which can condense into a highly volatile liquid on a cold day, in an ice bat ... * Tetraethynylmethane * Tetramethoxymethane External links * {{cite journal , doi = 10.1021/jo981779m , title = Molecular Structure of 3,3-Diethylpentane (Tetraethylmethane) in the Gas Phase as Determined by Electron Diffraction and ab Initio Calculations , journal = The Journal of Organic Chemistry , volume = 64 , issue = 12 , pages = 4226–4232 , year = 1999 , last1 = Alder , first1 = Roger W. , last2 = Allen , first2 = Paul R. , last3 = Hnyk , first3 = Drahomír , last4 = Rankin , first4 = David W. H. , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gasoline
Gasoline ( North American English) or petrol ( Commonwealth English) is a petrochemical product characterized as a transparent, yellowish, and flammable liquid normally used as a fuel for spark-ignited internal combustion engines. When formulated as a fuel for engines, gasoline is chemically composed of organic compounds derived from the fractional distillation of petroleum and later chemically enhanced with gasoline additives. It is a high-volume profitable product produced in crude oil refineries. The ability of a particular gasoline blend to resist premature ignition (which causes knocking and reduces efficiency in reciprocating engines) is measured by its octane rating. Tetraethyl lead was once widely used to increase the octane rating but is not used in modern automotive gasoline due to the health hazard. Aviation, off-road motor vehicles, and racing car engines still use leaded gasolines. Other substances are frequently added to gasoline to improve chemical st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead(II) Phosphate
Lead(II) phosphate is an ionic compound with chemical formula Pb3( P O4)2. Lead(II) phosphate is a long-lived electronically neutral reagent chemical. Despite limited tests on humans, it has been identified as a carcinogen based on tests on animals conducted by the EPA. Lead(II) phosphate appears as hexagonal, colorless crystals or as a white powder. Lead(II) phosphate is insoluble in water and alcohol but soluble in nitric acid (HNO3) and fused alkali metal hydroxides. When lead(II) phosphate is heated for decomposition it emits very toxic fumes containing Lead Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ... (Pb) and POx.Lewis, Richard J., Lewis, Richard J. Sr., (2008). Hazardous chemicals desk reference (sixth ed.) pg 831. Hoboken (NJ): John Wiley & Sons, Inc. Preparation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States asserts sovereignty over five Territories of the United States, major island territories and United States Minor Outlying Islands, various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's List of countries and dependencies by area, third-largest land area and List of countries and dependencies by population, third-largest population, exceeding 340 million. Its three Metropolitan statistical areas by population, largest metropolitan areas are New York metropolitan area, New York, Greater Los Angeles, Los Angel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
