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Amalgamated Zinc
Zinc amalgam is a solution of zinc in mercury. In practice the term refers to particles of zinc with a surface coating of the amalgam. A gray solid, it is typically used for reduction. It is written as Zn(Hg) in reactions. It is usually prepared by treating an aqueous suspension of zinc with mercuric chloride. Some zinc chloride is produced in the process. Uses * Used from ~1837 to reduce 'local action' which degraded operation of Voltaic piles. See History of the battery#Invention. * To reduce ferric to ferrous ions in solution. See Jones reductor. * To reduce ketones and aldehydes to alkanes via the Clemmensen reduction Clemmensen reduction is a chemical reaction described as a Redox, reduction of ketones or aldehydes to alkanes using zinc Amalgam (chemistry), amalgam and concentrated hydrochloric acid (HCl). This reaction is named after Erik Christian Clemmensen ... in acidic conditions. References Electrochemistry Metallurgy Zinc alloys Mercury (element) Amalga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc
Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic table. In some respects, zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity ( electrowinning). Zinc is an essential trace element for humans, animals, plants and for microorganisms and is necessary for prenatal and postnatal development. It is the second most abundant trace metal in humans after iron, an import ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketone
In organic chemistry, a ketone is an organic compound with the structure , where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group (a carbon-oxygen double bond C=O). The simplest ketone is acetone (where R and R' are methyl), with the formula . Many ketones are of great importance in biology and industry. Examples include many sugars (ketoses), many steroids, ''e.g.'', testosterone, and the solvent acetone. Nomenclature and etymology The word ''ketone'' is derived from ''Aketon'', an old German word for ''acetone''. According to the rules of IUPAC nomenclature, ketone names are derived by changing the suffix ''-ane'' of the parent alkane to ''-anone''. Typically, the position of the carbonyl group is denoted by a number, but traditional nonsystematic names are still generally used for the most important ketones, for example acetone and benzophenone. These nonsystematic names are considered retained IUPAC names, although some introdu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc Alloys
Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic table. In some respects, zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity ( electrowinning). Zinc is an essential trace element for humans, animals, plants and for microorganisms and is necessary for prenatal and postnatal development. It is the second most abundant trace metal in humans after iron, an important c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metallurgy
Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys. Metallurgy encompasses both the science and the technology of metals, including the production of metals and the engineering of metal components used in products for both consumers and manufacturers. Metallurgy is distinct from the craft of metalworking. Metalworking relies on metallurgy in a similar manner to how medicine relies on medical science for technical advancement. A specialist practitioner of metallurgy is known as a metallurgist. The science of metallurgy is further subdivided into two broad categories: chemical metallurgy and physical metallurgy. Chemical metallurgy is chiefly concerned with the reduction and oxidation of metals, and the chemical performance of metals. Subjects of study in chemical metallurgy include mineral processing, the extraction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrochemistry
Electrochemistry is the branch of physical chemistry concerned with the relationship between Electric potential, electrical potential difference and identifiable chemical change. These reactions involve Electron, electrons moving via an electronically conducting phase (typically an external electrical circuit, but not necessarily, as in Electroless nickel-phosphorus plating, electroless plating) between electrodes separated by an ionically conducting and electronically insulating electrolyte (or ionic chemical species, species in a Solution (chemistry), solution). When a chemical reaction is driven by an electrical Voltage, potential difference, as in electrolysis, or if a potential difference results from a chemical reaction as in an electric battery or fuel cell, it is called an ''electrochemical'' reaction. Unlike in other chemical reactions, in electrochemical reactions electrons are not transferred directly between atoms, ions, or molecules, but via the aforementioned electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clemmensen Reduction
Clemmensen reduction is a chemical reaction described as a Redox, reduction of ketones or aldehydes to alkanes using zinc Amalgam (chemistry), amalgam and concentrated hydrochloric acid (HCl). This reaction is named after Erik Christian Clemmensen, a Danish-American chemist. Clemmensen reduction conditions are particularly effective at reducing aryl-alkyl ketones, such as those formed in a Friedel-Crafts acylation. The two-step sequence of Friedel-Crafts acylation followed by Clemmensen reduction constitutes a classical strategy for the primary alkylation of arenes. Mechanism Despite the reaction being first discovered in 1914, the mechanism of the Clemmensen reduction remains obscure. Due to the Heterogeneous Reaction, heterogeneous nature of the reaction, mechanistic studies are difficult, and only a handful of studies have been disclosed. Mechanistic proposals generally invoke Organozinc chemistry, organozinc intermediates, sometimes including zinc carbenoids, either as d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkane
In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single. Alkanes have the general chemical formula . The alkanes range in complexity from the simplest case of methane (), where ''n'' = 1 (sometimes called the parent molecule), to arbitrarily large and complex molecules, like hexacontane () or 4-methyl-5-(1-methylethyl) octane, an isomer of dodecane (). The International Union of Pure and Applied Chemistry (IUPAC) defines alkanes as "acyclic branched or unbranched hydrocarbons having the general formula , and therefore consisting entirely of hydrogen atoms and saturated carbon atoms". However, some sources use the term to denote ''any'' saturated hydrocarbon, including those that are either monocyclic (i.e. the cycloalkanes) or polycycl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aldehyde
In organic chemistry, an aldehyde () (lat. ''al''cohol ''dehyd''rogenatum, dehydrogenated alcohol) is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl group. Aldehydes are a common motif in many chemicals important in technology and biology. Structure and bonding Aldehyde molecules have a central carbon atom that is connected by a double bond to oxygen, a single bond to hydrogen and another single bond to a third substituent, which is carbon or, in the case of formaldehyde, hydrogen. The central carbon is often described as being sp2- hybridized. The aldehyde group is somewhat polar. The bond length is about 120–122 picometers. Physical properties and characterization Aldehydes have properties that are diverse and that depend on the remainder of the molecule. Smaller aldehydes such as formaldehyde and acetaldehyde are solubl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jones Reductor
A Jones reductor is a device used to reduce aqueous solutions of metal ions. The active component is a zinc amalgam. Jones reductors have been used for preparing solutions of titanium(III), vanadium(II), chromium(II), molybdenum(III), niobium(III), europium(II), and uranium(III). Preparation and use Amalgamated zinc is prepared by treating zinc metal with a 2% solution of mercury(II) chloride. The metal may be in the granulated form or as shavings, wool, or powder. The amalgam forms on the surface of the zinc. After washing to remove salts, the amalgam is placed in a long glass tube, similar to a chromatography column, equipped with a stopcock. The amalgam is a more effective reducing agent than zinc metal. The effluent is often air-sensitive, requiring the use of air-free techniques. To use the reductor, the solution to be reduced is drawn through the tube. If the column is loosely packed, the solution may pass through without assistance. The length of the column or the flow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amalgam (chemistry)
An amalgam is an alloy of mercury (element), mercury with another metal. It may be a liquid, a soft paste or a solid, depending upon the proportion of mercury. These alloys are formed through metallic bonding, with the electrostatic attractive force of the conduction electrons working to bind all the positively charged metal ions together into a Crystal structure, crystal lattice structure. Almost all metals can form amalgams with mercury, the notable exceptions being iron, platinum, tungsten, and tantalum. Gold-mercury amalgam is used in the Gold extraction, extraction of gold from ore, and Amalgam (dentistry), dental amalgams are made with metals such as silver, copper, indium, tin and zinc. Important amalgams Zinc amalgam Zinc amalgam finds use in organic synthesis (e.g., for the Clemmensen reduction). It is the reducing agent in the Jones reductor, used in analytical chemistry. Formerly the zinc plates of dry battery (electric), batteries were amalgamated with a small amo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferrous Ion
In chemistry, iron(II) refers to the element iron in its +2 oxidation state. The adjective ''ferrous'' or the prefix ''ferro-'' is often used to specify such compounds, as in ''ferrous chloride'' for iron(II) chloride (). The adjective ''ferric'' is used instead for iron(III) salts, containing the cation Fe3+. The word ''ferrous'' is derived from the Latin word , meaning "iron". In ionic compounds (salts), such an atom may occur as a separate cation (positive ion) abbreviated as Fe2+, although more precise descriptions include other ligands such as water and halides. Iron(II) centres occur in coordination complexes, such as in the anion ferrocyanide, , where six cyanide ligands are bound the metal centre; or, in organometallic compounds, such as the ferrocene , where two cyclopentadienyl anions are bound to the FeII centre. Ferrous ions in biology All known forms of life require iron. Many proteins in living beings contain iron(II) centers. Examples of such metalloproteins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of The Battery
Batteries provided the main source of electricity before the development of electric generators and electrical grids around the end of the 19th century. Successive improvements in battery technology facilitated major electrical advances, from early scientific studies to the rise of telegraphs and telephones, eventually leading to portable computers, mobile phones, electric cars, and many other electrical devices. Students and engineers developed several commercially important types of battery. "Wet cells" were open containers that held liquid electrolyte and metallic electrodes. When the electrodes were completely consumed, the wet cell was renewed by replacing the electrodes and electrolyte. Open containers are unsuitable for mobile or portable use. Wet cells were used commercially in the telegraph and telephone systems. Early electric cars used semi-sealed wet cells. One important classification for batteries is by their life cycle. "Primary" batteries can produce current ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
