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Magnesium Acetate
Anhydrous magnesium acetate has the chemical formula Mg(C2H3O2)2 and in its hydrated form, magnesium acetate tetrahydrate, it has the chemical formula Mg(CH3COO)2 • 4H2O. In this compound magnesium has an oxidation state of 2+. Magnesium acetate is the magnesium salt of acetic acid. It is deliquescent and upon heating, it decomposes to form magnesium oxide. Magnesium acetate is commonly used as a source of magnesium in biological reactions. Physical properties Magnesium acetate appears as white hygroscopic crystals. It smells like acetic acid and is soluble in water. When it is in an aqueous solution its pH will be on the alkaline side of neutral. Storage Due to the fact that it is very hygroscopic, it must be stored away from water. It is also incompatible with strong oxidizers and should not be mixed with them. Synthesis Synthesis of magnesium acetate from the reaction of magnesium hydroxide with acetic acid. :2 CH3COOH + Mg(OH)2 → (CH3COO)2Mg + 2 H2O Magnesium carbo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Acetate
Calcium acetate is a chemical compound which is a calcium salt of acetic acid. It has the formula Ca(C2H3O2)2. Its standard name is calcium acetate, while calcium ethanoate is the systematic name. An older name is acetate of lime. The anhydrous form is very hygroscopic; therefore the monohydrate (Ca(CH3COO)2•H2O) is the common form. Production Calcium acetate can be prepared by soaking calcium carbonate (found in eggshells, or in common carbonate rocks such as limestone or marble) or hydrated lime in vinegar: :CaCO3(s) + 2CH3COOH(aq) → Ca(CH3COO)2(aq) + H2O(l) + CO2(g) :Ca(OH)2(s) + 2CH3COOH(aq) → Ca(CH3COO)2(aq) + 2H2O(l) Since both reagents would have been available pre-historically, the chemical would have been observable as crystals then. Uses * In kidney disease, blood levels of phosphate may rise (called hyperphosphatemia) leading to bone problems. Calcium acetate binds phosphate in the diet to lower blood phosphate levels. * Calcium acetate is used as a food addit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnesium
Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic table) it occurs naturally only in combination with other elements and it almost always has an oxidation state of +2. It reacts readily with air to form a thin passivation coating of magnesium oxide that inhibits further corrosion of the metal. The free metal burns with a brilliant-white light. The metal is obtained mainly by electrolysis of magnesium salts obtained from brine. It is less dense than aluminium and is used primarily as a component in strong and lightweight alloys that contain aluminium. In the cosmos, magnesium is produced in large, aging stars by the sequential addition of three helium nuclei to a carbon nucleus. When such stars explode as supernovas, much of the magnesium is expelled into the interstellar medium where it ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetic Acid
Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component of vinegar apart from water and other trace elements. Acetic acid is the second simplest carboxylic acid (after formic acid). It is an important Reagent, chemical reagent and industrial chemical, used primarily in the production of cellulose acetate for photographic film, polyvinyl acetate for wood Adhesive, glue, and synthetic fibres and fabrics. In households, diluted acetic acid is often used in descaling agents. In the food industry, acetic acid is controlled by the E number, food additive code E260 as an acidity regulator and as a condiment. In biochemistry, the acetyl group, derived from acetic acid, is fundamental to all forms of life. When bound to coenzyme A, it is central to the metabolism of carbohydrates and fats. The global ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hygroscopy
Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance's molecules, adsorbing substances can become physically changed, e.g., changing in volume, boiling point, viscosity or some other physical characteristic or property of the substance. For example, a finely dispersed hygroscopic powder, such as a salt, may become clumpy over time due to collection of moisture from the surrounding environment. ''Deliquescent'' materials are sufficiently hygroscopic that they absorb so much water that they become liquid and form an aqueous solution. Etymology and pronunciation The word ''hygroscopy'' () uses combining forms of '' hygro-'' and '' -scopy''. Unlike any other ''-scopy'' word, it no longer refers to a viewing or imaging mode. It did begin that way, with the word ''hygroscope'' referring in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnesium Oxide
Magnesium oxide ( Mg O), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions held together by ionic bonding. Magnesium hydroxide forms in the presence of water (MgO + H2O → Mg(OH)2), but it can be reversed by heating it to remove moisture. Magnesium oxide was historically known as magnesia alba (literally, the white mineral from Magnesia), to differentiate it from ''magnesia negra'', a black mineral containing what is now known as manganese. Related oxides While "magnesium oxide" normally refers to MgO, the compound magnesium peroxide MgO2 is also known. According to evolutionary crystal structure prediction, MgO2 is thermodynamically stable at pressures above 116 GPa (gigapascals), and a semiconducting suboxide Mg3O2 is thermodynamically stable above 500 GPa. Because of its stability, MgO is used as a model sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Elements
American Elements is a global manufacturer and distributor of advanced materials with a more than 35,000-page online product catalog and compendium of information on the chemical elements, advanced materials, and high technology applications. The company's headquarters and educational programs are based in Los Angeles, California. Its research and production facilities are located in Salt Lake City, Utah; Monterrey, Mexico; Baotou, China; and Manchester, UK. History American Elements began as a toll chemical manufacturer and refiner serving U.S. mining companies by producing metal-based chemicals from their deposits. In 1998, its two largest customers, the Unocal/Molycorp rare-earth mine in Mountain Pass, California and the Rhodia rare-earth refinery in Freeport, Texas closed, ending domestic U.S. rare-earth production. In response, the company established mining joint ventures in Inner Mongolia, China and in 1999 became one of the first post-Cold War companies to export rare-eart ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hygroscopic
Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance's molecules, adsorbing substances can become physically changed, e.g., changing in volume, boiling point, viscosity or some other physical characteristic or property of the substance. For example, a finely dispersed hygroscopic powder, such as a salt, may become clumpy over time due to collection of moisture from the surrounding environment. ''Deliquescent'' materials are sufficiently hygroscopic that they absorb so much water that they become liquid and form an aqueous solution. Etymology and pronunciation The word ''hygroscopy'' () uses combining forms of '' hygro-'' and '' -scopy''. Unlike any other ''-scopy'' word, it no longer refers to a viewing or imaging mode. It did begin that way, with the word ''hygroscope'' referring in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clamond Basket
A Clamond basket is a kind of gas mantle, invented in the 1880s by the Parisian Charles Clamond, and which he later patented in the United States. It was the first economically practical gas mantle, since prior mantles had involved expensive materials like platinum and iridium. Producing the gauze A dense water-based slurry of magnesium hydroxide and magnesium acetate is forced through a small hole in a metal plate. On exposure to air it solidifies sufficiently to make a thread which is shaped into the required form. Use When exposed to a hot flame, a basket made of this composite gauze would burn away the acetate, leaving a brittle but serviceable magnesia (magnesium oxide Magnesium oxide ( Mg O), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions ...) basket behind as the mantle. Charles Lungren subsequently ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas Mantle
A Coleman white gas lantern mantle glowing at full brightness An incandescent gas mantle, gas mantle or Welsbach mantle is a device for generating incandescent bright white light when heated by a flame. The name refers to its original heat source in gas lights which illuminated the streets of Europe and North America in the late 19th century. ''Mantle'' refers to the way it hangs like a cloak above the flame. Gas mantles were also used in portable camping lanterns, pressure lanterns and some oil lamps. Gas mantles are usually sold as fabric items, which, because of impregnation with metal nitrates, burns away to leave a rigid but fragile mesh of metal oxides when heated during initial use; these metal oxides produce light from the heat of the flame whenever used. Thorium dioxide was commonly a major component; being radioactive, it has led to concerns about the safety of those involved in manufacturing mantles. Normal use, however, poses minimal health risk. Mechanism l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnesium Hydroxide
Magnesium hydroxide is the inorganic compound with the chemical formula Mg(OH)2. It occurs in nature as the mineral brucite. It is a white solid with low solubility in water (). Magnesium hydroxide is a common component of antacids, such as milk of magnesia. Preparation Treating the solution of different soluble magnesium salts with alkaline water induces the precipitation of the solid hydroxide Mg(OH)2: :Mg2+ + 2OH− → Mg(OH)2 As is the second most abundant cation present in seawater after , it can be economically extracted directly from seawater by alkalinisation as described here above. On an industrial scale, Mg(OH)2 is produced by treating seawater with lime (Ca(OH)2). A volume of (or 160,000 US gallons) of seawater gives about one ton of Mg(OH)2. Ca(OH)2 is far more soluble than Mg(OH)2 and drastically increases the pH value of seawater from 8.2 to 12.5. The less soluble precipitates because of the common ion effect due to the added by the dissolution of : : ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primase
DNA primase is an enzyme involved in the replication of DNA and is a type of RNA polymerase. Primase catalyzes the synthesis of a short RNA (or DNA in some living organisms) segment called a primer complementary to a ssDNA (single-stranded DNA) template. After this elongation, the RNA piece is removed by a 5' to 3' exonuclease and refilled with DNA. Function In bacteria, primase binds to the DNA helicase forming a complex called the primosome. Primase is activated by the helicase where it then synthesizes a short RNA primer approximately 11 ±1 nucleotides long, to which new nucleotides can be added by DNA polymerase. Archaeal and eukaryote primases are heterodimeric proteins with one large regulatory and one minuscule catalytic subunit. The RNA segments are first synthesized by primase and then elongated by DNA polymerase. Then the DNA polymerase forms a protein complex with two primase subunits to form the alpha DNA Polymerase primase complex. Primase is one of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnesium Compounds
Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic table) it occurs naturally only in combination with other elements and it almost always has an oxidation state of +2. It reacts readily with air to form a thin passivation coating of magnesium oxide that inhibits further corrosion of the metal. The free metal burns with a brilliant-white light. The metal is obtained mainly by electrolysis of magnesium salts obtained from brine. It is less dense than aluminium and is used primarily as a component in strong and lightweight alloys that contain aluminium. In the cosmos, magnesium is produced in large, aging stars by the sequential addition of three helium nuclei to a carbon nucleus. When such stars explode as supernovas, much of the magnesium is expelled into the interstellar medium where it ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
