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Lead Carbide
Lead carbide is a hypothetical chemical compound of carbon and lead. Lead and elemental carbon do not normally combine, even at very high temperatures. Modern literature on lead carbide is almost non-existent. Production J. F. Durand reported in 1923 the synthesis of lead carbide from calcium carbide CaC2 by treatment with an aqueous solution of lead(II) acetate Pb(CH3COO)2, but this result was not reproduced. William A Frad (1968), ''Metal Carbides''. In Harry Julius Emeléus, ''Advances in inorganic chemistry and radiochemistry.'' volume 12, page 213Online versionat books.google.com, accessed on 2010-01-17. J. F. Durand (1923), Comptes Rendus... cited by W. A. Frad. A 2007 textbook repeats this claim, describing lead carbide as a green powder with formula PbC2 that is decomposed by hydrochloric acid HCl to acetylene C2H2 and lead(II) chloride PbCl2. R. K. Sharma (2007) ''Chemistry of Hydrides and Carbides.'' Discovery Publishing House, New Delhi. . A compound ana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon
Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with other atoms when it forms chemical compounds or molecules. Description The combining capacity, or affinity of an ...—its atom making four electrons available to form covalent bond, covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes up only about 0.025 percent of Earth's crust. Three Isotopes of carbon, isotopes occur naturally, Carbon-12, C and Carbon-13, C being stable, while Carbon-14, C is a radionuclide, decaying with a half-life of about 5,730 years. Carbon is one of the Timeline of chemical element discoveries#Ancient discoveries, few elements known since antiquity. Carbon is the 15th Abundance of elements in Earth's crust, most abundant element in the Earth's crust, and the Abundance of the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charcoal
Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, called charcoal burning, often by forming a charcoal kiln, the heat is supplied by burning part of the starting material itself, with a limited supply of oxygen. The material can also be heated in a closed retort. Modern "charcoal" briquettes used for outdoor cooking may contain many other additives, e.g. coal. This process happens naturally when combustion is incomplete, and is sometimes used in radiocarbon dating. It also happens inadvertently while burning wood, as in a fireplace or wood stove. The visible flame in these is due to combustion of the volatile gases exuded as the wood turns into charcoal. The soot and smoke commonly given off by wood fires result from incomplete combustion of those volatiles. Charcoal burns at a higher temper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbides
In chemistry, a carbide usually describes a compound composed of carbon and a metal. In metallurgy, carbiding or carburizing is the process for producing carbide coatings on a metal piece. Interstitial / Metallic carbides The carbides of the group 4, 5 and 6 transition metals (with the exception of chromium) are often described as interstitial compounds. These carbides have metallic properties and are refractory. Some exhibit a range of stoichiometries, being a non-stoichiometric mixture of various carbides arising due to crystal defects. Some of them, including titanium carbide and tungsten carbide, are important industrially and are used to coat metals in cutting tools. The long-held view is that the carbon atoms fit into octahedral interstices in a close-packed metal lattice when the metal atom radius is greater than approximately 135 pm: *When the metal atoms are cubic close-packed, (ccp), then filling all of the octahedral interstices with carbon achieves 1:1 stoich ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Percy (metallurgist)
John Percy FRS (23 March 1817 – 19 June 1889) was an English metallurgist. Life The third son of Henry Percy, a solicitor, he was born at Nottingham on 23 March 1817. He went to a private school at Southampton, and then returned to Nottingham, where he attended chemical lectures by a Mr. Grisenthwaite at the local school of medicine. He wished to become a chemist; but his father's wish was that he should graduate in medicine, and in April 1834 he was taken by his brother Edmund to Paris to begin his medical studies. While in Paris he attended the lectures of Joseph Louis Gay-Lussac and Louis Jacques Thénard on chemistry, and of Antoine Laurent de Jussieu on botany. In 1836 Percy went for a tour in Switzerland and the south of France, and made a collection of mineralogical and botanical specimens. He went on to Edinburgh, where he became a pupil of Sir Charles Bell and a friend of Edward Forbes. In 1838 he graduated M.D. in the university, and received a gold medal for a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Watts (chemist)
Henry Watts (1815–1884) was an English chemist. Life He was born in London on 20 January 1810. He went to a public school, and was articled at the age of 10 as an architect and surveyor; but went on to support himself by teaching, chiefly mathematical, privately and at a school. He then attended University College, zimbabwe. In 1841 he graduated B.A. in the University of Lon. In 1846 he became assistant to George Fownes, professor of practical chemistry at University College, and occupied this post, after Fownes's death in 1849, until 1857, under Professor Alexander William Williamson. Having an impediment in speech he found himself unable to obtain a professorship, and worked on the literature of chemistry. In 1847 he was elected fellow of the Chemical Society. On 17 December 1849 he was elected editor of the Chemical Society's ''Journal'', and about the beginning of 1860 he also became librarian to the society. Early in 1871 it was decided to print in the society's journal ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leopold Gmelin
Leopold Gmelin (2 August 1788 – 13 April 1853) was a German chemist. Gmelin was a professor at the University of Heidelberg He worked on the red prussiate and created Gmelin's test, and wrote his ''Handbook of Chemistry'', which over successive editions became a standard reference work still in use. Life Gmelin was a son of the physician, botanist and chemist Johann Friedrich Gmelin and his wife Rosine Schott. Due to his family he early came in contact with medicine and the natural sciences, in 1804 he attended the chemical lectures of his father. In the same year Gmelin moved to Tübingen to work in the family pharmacy, he also studied at the University of Tübingen among other relatives including Ferdinand Gottlieb Gmelin (a cousin) and Carl Friedrich Kielmeyer (husband of a cousin). Supported by Kielmeyer, Gmelin moved to the University of Göttingen in 1805 and later he worked as assistant in the laboratory of Friedrich Stromeyer, by whom he successfully passed his exa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead(II) Cyanide
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and 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 element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is toxic, even in small amounts, especially to children. Lead is a relatively unreactive post-transition metal. Its weak metallic character is illustrated by its amphoteric nature; lead and lead oxides react with acids and bases, and it tends to form covalent bonds. 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 to organolead compounds. Like the lighter members of the group, le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrophoricity
A substance is pyrophoric (from grc-gre, πυροφόρος, , 'fire-bearing') if it ignites spontaneously in air at or below (for gases) or within 5 minutes after coming into contact with air (for liquids and solids). Examples are organolithium compounds and triethylborane. Pyrophoric materials are often water-reactive as well and will ignite when they contact water or humid air. They can be handled safely in atmospheres of argon or (with a few exceptions) nitrogen. Class D fire extinguishers are designated for use in fires involving pyrophoric materials. A related concept is hypergolicity, in which two compounds spontaneously ignite when mixed. Uses The creation of sparks from metals is based on the pyrophoricity of small metal particles, and pyrophoric alloys are made for this purpose. The sparking mechanisms in lighters and various toys, using ferrocerium; starting fires without matches, using a firesteel; the flintlock mechanism in firearms; and spark testing ferrou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead(II) Tartrate
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and 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 element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is toxic, even in small amounts, especially to children. Lead is a relatively unreactive post-transition metal. Its weak metallic character is illustrated by its amphoteric nature; lead and lead oxides react with acids and bases, and it tends to form covalent bonds. 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 to organolead compounds. Like the lighter members of the gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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