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Vladimir Markovnikov
Vladimir Vasilyevich Markovnikov (russian: Влади́мир Васи́льевич Марко́вников), also spelled as Markownikoff ( – 11 February 1904), was a Russian chemist. Early life and education Markovnikov studied economics at the University of Kazan; during his studies, under the Russian cameral system, he also studied chemistry. Career After a conflict with that university, Markovnikov was appointed professor at the University of Odessa in 1871 and, two years later, at the University of Moscow, where he stayed the rest of his career. He was elected as a member to the American Philosophical Society in 1901. Work Markovnikov is best known for Markovnikov's rule, elucidated in 1869 to describe addition reactions of H-X (where 'X' represents a halogen) to alkenes. According to this rule, the nucleophilic X- adds to the carbon atom with fewer hydrogen atoms, while the proton adds to the carbon atom with more hydrogen atoms bonded to it. Thus, hydrogen chlorid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knyaginino, Nizhny Novgorod Oblast
Knyaginino (russian: Княги́нино) is a town and the administrative center of Knyagininsky District in Nizhny Novgorod Oblast, Russia, located on the Imza River, southeast of Nizhny Novgorod, the administrative center of the oblast. Population: History It was first mentioned in the second half of the 16th century as an estate of Mikhail Vorotynsky. In 1779, it was granted town rights. At that time, it was known as Knyaginin (); this name was used until 1917. In 1926, it was demoted to a rural locality ('' selo'') status. It was granted urban-type settlement status in 1968 and town status in 1998. Administrative and municipal status Within the framework of administrative divisions, Knyaginino serves as the administrative center of Knyagininsky District.Order #3-od As an administrative division, it is, together with the village of Gorshkovo, incorporated within Knyagininsky District as the town of district significance Town of district significance is an administr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Markovnikov's Rule
In organic chemistry, Markovnikov's rule or Markownikoff's rule describes the outcome of some addition reactions. The rule was formulated by Russian chemist Vladimir Markovnikov in 1870. Explanation The rule states that with the addition of a protic acid HX or other polar reagent to an asymmetric alkene, the acid hydrogen (H) or electropositive part gets attached to the carbon with more hydrogen substituents, and the halide (X) group or electronegative part gets attached to the carbon with more alkyl substituents. This is in contrast to Markovnikov's original definition, in which the rule is stated that the X component is added to the carbon with the fewest hydrogen atoms while the hydrogen atom is added to the carbon with the greatest number of hydrogen atoms. The same is true when an alkene reacts with water in an addition reaction to form an alcohol which involve formation of carbocations. The hydroxyl group (OH) bonds to the carbon that has the greater number of carbon– ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemists From The Russian Empire
A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms. Chemists carefully measure substance proportions, chemical reaction rates, and other chemical properties. In Commonwealth English, pharmacists are often called chemists. Chemists use their knowledge to learn the composition and properties of unfamiliar substances, as well as to reproduce and synthesize large quantities of useful naturally occurring substances and create new artificial substances and useful processes. Chemists may specialize in any number of subdisciplines of chemistry. Materials scientists and metallurgists share much of the same education and skills with chemists. The work of chemists is often related to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1904 Deaths
Nineteen or 19 may refer to: * 19 (number), the natural number following 18 and preceding 20 * one of the years 19 BC, AD 19, 1919, 2019 Films * ''19'' (film), a 2001 Japanese film * ''Nineteen'' (film), a 1987 science fiction film Music * 19 (band), a Japanese pop music duo Albums * ''19'' (Adele album), 2008 * ''19'', a 2003 album by Alsou * ''19'', a 2006 album by Evan Yo * ''19'', a 2018 album by MHD * ''19'', one half of the double album ''63/19'' by Kool A.D. * '' Number Nineteen'', a 1971 album by American jazz pianist Mal Waldron * ''XIX'' (EP), a 2019 EP by 1the9 Songs * "19" (song), a 1985 song by British musician Paul Hardcastle. * "Nineteen", a song by Bad4Good from the 1992 album '' Refugee'' * "Nineteen", a song by Karma to Burn from the 2001 album ''Almost Heathen ''Almost Heathen'' is the third studio album by the stoner rock band Karma to Burn, released in 2001 via Spitfire Records. It was the last album released before their seven-year disban ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1838 Births
Events January–March * January 10 – A fire destroys Lloyd's Coffee House and the Royal Exchange in London. * January 11 – At Morristown, New Jersey, Samuel Morse, Alfred Vail and Leonard Gale give the first public demonstration of Morse's new invention, the telegraph. * January 11 - A 7.5 earthquake strikes the Romanian district of Vrancea causing damage in Moldavia and Wallachia, killing 73 people. * January 21 – The first known report about the lowest temperature on Earth is made, indicating in Yakutsk. * February 6 – Boer explorer Piet Retief and 60 of his men are massacred by King Dingane kaSenzangakhona of the Zulu people, after Retief accepts an invitation to celebrate the signing of a treaty, and his men willingly disarm as a show of good faith. * February 17 – Weenen massacre: Zulu impis massacre about 532 Voortrekkers, Khoikhoi and Basuto around the site of Weenen in South Africa. * February 24 – U.S. Representatives William ... [...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—its atom making four electrons available to form 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 occur naturally, C and C being stable, while C is a radionuclide, decaying with a half-life of about 5,730 years. Carbon is one of the few elements known since antiquity. Carbon is the 15th most abundant element in the Earth's crust, and the fourth most abundant element in the universe by mass after hydrogen, helium, and oxygen. Carbon's abundance, its unique diversity of organic compounds, and its unusual ability to form polymers at the temperatures commonly encountered on Earth, enables this element to serve as a common element of all known life. It is the second most abundant element in the human body by mass (about 18.5%) after oxygen. The atoms of carbo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; Greeves, N. and Warren, S. (2012) ''Organic Chemistry''. Oxford University Press. pp. 1–15. . Study of structure determines their structural formula. Study of properties includes physical and chemical properties, and evaluation of chemical reactivity to understand their behavior. The study of organic reactions includes the chemical synthesis of natural products, drugs, and polymers, and study of individual organic molecules in the laboratory and via theoretical ( in silico) study. The range of chemicals studied in organic chemistry includes hydrocarbons (compounds containing only carbon and hydrogen) as well as compounds based on carbon, but also containing other elements, especially oxygen, nitrogen, sulfur, phosphorus (i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxide
In chemistry, peroxides are a group of compounds with the structure , where R = any element. The group in a peroxide is called the peroxide group or peroxo group. The nomenclature is somewhat variable. The most common peroxide is hydrogen peroxide (), colloquially known simply as "peroxide". It is marketed as solutions in water at various concentrations. Many organic peroxides are known as well. In addition to hydrogen peroxide, some other major classes of peroxides are: * Peroxy acids, the peroxy derivatives of many familiar acids, examples being peroxymonosulfuric acid and peracetic acid, and their salts, one example of which is potassium peroxydisulfate. * Main group peroxides, compounds with the linkage (E = main group element). * Metal peroxides, examples being barium peroxide (), sodium peroxide Sodium peroxide is an inorganic compound with the formula Na2O2. This yellowish solid is the product of sodium ignited in excess oxygen. It is a strong base. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morris S
Morris may refer to: Places Australia *St Morris, South Australia, place in South Australia Canada * Morris Township, Ontario, now part of the municipality of Morris-Turnberry * Rural Municipality of Morris, Manitoba ** Morris, Manitoba, a town mostly surrounded by the municipality * Morris (electoral district), Manitoba (defunct) * Rural Municipality of Morris No. 312, Saskatchewan United States ;Communities * Morris, Alabama, a town * Morris, Connecticut, a town * Morris, Georgia, an unincorporated community * Morris, Illinois, a city * Morris, Indiana, an unincorporated community * Morris, Minnesota, a city * Morristown, New Jersey, a town * Morris (town), New York ** Morris (village), New York * Morris, Oklahoma, a city * Morris, Pennsylvania, an unincorporated community * Morris, West Virginia, an unincorporated community * Morris, Kanawha County, West Virginia, a ghost town * Morris, Wisconsin, a town * Morris Township (other) ;Counties and oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkene
In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.H. Stephen Stoker (2015): General, Organic, and Biological Chemistry'. 1232 pages. Two general types of monoalkenes are distinguished: terminal and internal. Also called α-olefins, terminal alkenes are more useful. However, the International Union of Pure and Applied Chemistry (IUPAC) recommends using the name "alkene" only for acyclic hydrocarbons with just one double bond; alkadiene, alkatriene, etc., or polyene for acyclic hydrocarbons with two or more double bonds; cycloalkene, cycloalkadiene, etc. for cyclic ones; and "olefin" for the general class – cyclic or acyclic, with one or more double bonds. Acyclic alkenes, with only one double bond and no other functional groups (also known as mono-enes) form a homologous series of hydrocarbons with the general formula with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halogen
The halogens () are a group in the periodic table consisting of five or six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), and tennessine (Ts). In the modern IUPAC nomenclature, this group is known as group 17. The word "halogen" means "salt former" (or "salt maker"). When halogens react with metals, they produce a wide range of salts, including calcium fluoride, sodium chloride (common table salt), silver bromide and potassium iodide. The group of halogens is the only periodic table group that contains elements in three of the main states of matter at standard temperature and pressure. All of the halogens form acids when bonded to hydrogen. Most halogens are typically produced from minerals or salts. The middle halogens—chlorine, bromine, and iodine—are often used as disinfectants. Organobromides are the most important class of flame retardants, while elemental halogens are dangerous and can be toxic. His ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Philosophical Society
The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and community outreach. Considered the first learned society in the United States, it has about 1,000 elected members, and by April 2020 had had only 5,710 members since its creation. Through research grants, published journals, the American Philosophical Society Museum, an extensive library, and regular meetings, the society supports a variety of disciplines in the humanities and the sciences. Philosophical Hall, now a museum, is just east of Independence Hall in Independence National Historical Park; it was designated a National Historic Landmark in 1965. History The Philosophical Society, as it was originally called, was founded in 1743 by Benjamin Franklin, James Alexander, Francis Hopkinson, John Bartram, Philip Syng, Jr. and others as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
