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Calcium Cyanamide
Calcium cyanamide, also known as Calcium carbondiamide, Calcium cyan-2°-amide or Calcium cyanonitride is the inorganic compound with the formula CaCN2. It is the calcium salt of the cyanamide () anion. This chemical is used as fertilizer and is commercially known as nitrolime. It also has herbicide, herbicidal activity and in the 1950s was marketed as cyanamid. It was first synthesized in 1898 by Adolph Frank and Nikodem Caro (Frank–Caro process). History In their search for a new process for producing cyanides for gold cyanidation, cyanide leaching of gold, Frank and Caro discovered the ability of alkaline earth carbides to absorb atmospheric nitrogen at high temperatures. Fritz Rothe, a colleague of Frank and Caro, succeeded in 1898 in overcoming problems with the use of calcium carbide and clarified that at around 1,100 °C not calcium cyanide but calcium cyanamide is formed in the reaction. In fact, the initial target product sodium cyanide can also be obtained from c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanamide
Cyanamide is an organic compound with the formula C N2 H2. This white solid is widely used in agriculture and the production of pharmaceuticals and other organic compounds. It is also used as an alcohol-deterrent drug. The molecule features a nitrile group attached to an amino group. Derivatives of this compound are also referred to as cyanamides, the most common being calcium cyanamide (CaCN2). Tautomers and self-condensations Containing both a nucleophilic and electrophilic site within the same molecule, cyanamide undergoes various reactions with itself. Cyanamide exists as two tautomers, one with the connectivity N≡C–NH2 and the other with the formula HN=C=NH (" carbodiimide" tautomer). The N≡C–NH2 form dominates, but in a few reactions (e.g. silylation) the diimide form appears to be important. Cyanamide dimerizes to give 2-cyanoguanidine (dicyandiamide). This dimerization is hindered or reversed by acids and is inhibited by low temperatures. The cyclic trime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcohol (drug)
Alcohol, sometimes referred to by the chemical name ethanol, is the active ingredient in alcoholic drinks such as beer, wine, and distilled spirits (hard liquor). Alcohol is a central nervous system (CNS) depressant, decreasing Action potential, electrical activity of neurons in the brain, which causes the characteristic effects of alcohol intoxication ("drunkenness"). Among other effects, alcohol produces euphoria, anxiolytic, decreased anxiety, increased sociability, sedation, and impairment of cognitive, memory, motor control, motor, and sense, sensory function. Alcohol has a variety of adverse effects. Short-term effects of alcohol consumption, Short-term adverse effects include generalized impairment of neurocognitive function, dizziness, nausea, vomiting, and symptoms of hangover. Alcohol is addiction, addictive and can result in alcohol use disorder, Substance dependence, dependence, and Alcohol withdrawal syndrome, withdrawal upon cessation. The long-term effects of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melamine
Melamine is an organic compound with the formula C3H6N6. This white solid is a trimer (chemistry), trimer of cyanamide, with a 1,3,5-Triazine, 1,3,5-triazine skeleton. Like cyanamide, it contains 66% nitrogen by mass, and its derivatives have fire retardant, fire-retardant properties due to its release of nitrogen gas when burned or charred. Melamine can be combined with formaldehyde and other agents to produce melamine resins. Such resins are characteristically durable thermosetting plastic used in high–pressure decorative laminates such as Formica (plastic), Formica, melamine dinnerware including cooking utensils, plates, and plastic products, laminate flooring, and dry erase boards. Melamine foam is used as insulation and soundproofing material, and in polymeric cleaning products such as Magic Eraser. Melamine-formaldehyde resin tableware was evaluated by the Taiwan Consumers' Foundation to have 20,000 parts per billion of free melamine that could migrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Cyanide
Calcium cyanide is the inorganic compound with the formula Ca(CN)2. It is the calcium salt derived from hydrocyanic acid. It is a white solid, although the pure material is rarely encountered. It slowly hydrolyses in solution or moist air to release hydrogen cyanide and is very toxic. Preparation Solutions of calcium cyanide can be prepared by treating calcium hydroxide with hydrogen cyanide. Solid calcium cyanide is produced commercially by heating calcium cyanamide with sodium chloride. The reaction is incomplete. The product is only of 50% purity, other components being sodium cyanide, calcium cyanamide, and carbon. Because of the carbon impurity, the solid is black, hence material is often called black cyanide. Reactivity At temperatures around 600 °C, calcium cyanide converts to calcium cyanamide:"Production of Hydrocyanic Acid" ''United States Patent Office.'' 1933.(accessed April 22, 2012). :Ca(CN)2 → CaCN2 + C It is suspected that this reaction is one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Carbonate
Sodium carbonate (also known as washing soda, soda ash, sal soda, and soda crystals) is the inorganic compound with the formula and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water. Historically, it was extracted from the ashes of plants grown in sodium-rich soils, and because the ashes of these sodium-rich plants were noticeably different from ashes of wood (once used to produce potash), sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process, as well as by carbonating sodium hydroxide which is made using the chloralkali process. Hydrates Sodium carbonate is obtained as three hydrates and as the anhydrous salt: * sodium carbonate decahydrate ( natron), Na2CO3·10H2O, which readily effloresces to form the monohydrate. * sodium carbonate heptahydrate (not known in mineral form), Na2CO3·7H2O. * sodium carbonate monohydrate ( thermonatr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melting
Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid. This occurs when the internal energy of the solid increases, typically by the application of heat or pressure, which increases the substance's temperature to the melting point. At the melting point, the ordering of ions or molecules in the solid breaks down to a less ordered state, and the solid melts to become a liquid. Substances in the molten state generally have reduced viscosity as the temperature increases. An exception to this principle is elemental sulfur, whose viscosity increases in the range of 130 °C to 190 °C due to polymerization. Some organic compounds melt through mesophases, states of partial order between solid and liquid. First order phase transition From a thermodynamics point of view, at the melting point the change in Gibbs free energy ''∆G'' of the substances is zero, but there are non-zero changes in the entha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonia
Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pungent smell. It is widely used in fertilizers, refrigerants, explosives, cleaning agents, and is a precursor for numeous chemicals. Biologically, it is a common nitrogenous waste, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to fertilisers. Around 70% of ammonia produced industrially is used to make fertilisers in various forms and composition, such as urea and diammonium phosphate. Ammonia in pure form is also applied directly into the soil. Ammonia, either directly or indirectly, is also a building block for the synthesis of many chemicals. In many countries, it is classified as an List of extremely hazardous substances, extremely hazardous substance. Ammonia is toxic, cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Cyanamide
Cyanamide is an organic compound with the formula C N2 H2. This white solid is widely used in agriculture and the production of pharmaceuticals and other organic compounds. It is also used as an alcohol-deterrent drug. The molecule features a nitrile group attached to an amino group. Derivatives of this compound are also referred to as cyanamides, the most common being calcium cyanamide (CaCN2). Tautomers and self-condensations Containing both a nucleophilic and electrophilic site within the same molecule, cyanamide undergoes various reactions with itself. Cyanamide exists as two tautomers, one with the connectivity N≡C–NH2 and the other with the formula HN=C=NH (" carbodiimide" tautomer). The N≡C–NH2 form dominates, but in a few reactions (e.g. silylation) the diimide form appears to be important. Cyanamide dimerizes to give 2-cyanoguanidine (dicyandiamide). This dimerization is hindered or reversed by acids and is inhibited by low temperatures. The cyclic trimer i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transformation Of Calcium Cyanamide
Transformation may refer to: Science and mathematics In biology and medicine * Metamorphosis, the biological process of changing physical form after birth or hatching * Malignant transformation, the process of cells becoming cancerous * Transformation (genetics), genetic alteration of a cell by DNA uptake In mathematics * Transformation (function), concerning functions from sets to themselves. For functions in the broader sense, see function (mathematics). **Affine transformation, in geometry **Linear transformation between modules in linear algebra. Also called a linear map. ***Transformation matrix which represent linear maps in linear algebra. *Integral transform, between a function in one domain to a function in another * Natural transformation between functors in category theory. * Unitary transformation, between two Hilbert spaces * Geometric transformation, between sets of points in geometry **Infinitesimal transformation, a limiting case of a geometrical transformatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lattice Constant
A lattice constant or lattice parameter is one of the physical dimensions and angles that determine the geometry of the unit cells in a crystal lattice, and is proportional to the distance between atoms in the crystal. A simple cubic crystal has only one lattice constant, the distance between atoms, but, in general, lattices in three dimensions have six lattice constants: the lengths ''a'', ''b'', and ''c'' of the three cell edges meeting at a vertex, and the angles ''α'', ''β'', and ''γ'' between those edges. The crystal lattice parameters ''a'', ''b'', and ''c'' have the dimension of length. The three numbers represent the size of the unit cell, that is, the distance from a given atom to an identical atom in the same position and orientation in a neighboring cell (except for very simple crystal structures, this will not necessarily be distance to the nearest neighbor). Their SI unit is the meter, and they are traditionally specified in angstroms (Å); an angstrom being 0.1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Group
In mathematics, physics and chemistry, a space group is the symmetry group of a repeating pattern in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of the pattern that leave it unchanged. In three dimensions, space groups are classified into 219 distinct types, or 230 types if chiral copies are considered distinct. Space groups are discrete cocompact groups of isometries of an oriented Euclidean space in any number of dimensions. In dimensions other than 3, they are sometimes called Bieberbach groups. In crystallography, space groups are also called the crystallographic or Fedorov groups, and represent a description of the symmetry of the crystal. A definitive source regarding 3-dimensional space groups is the ''International Tables for Crystallography'' . History Space groups in 2 dimensions are the 17 wallpaper groups which have been known for several centuries, though the proof that the list ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexagonal Crystal System
In crystallography, the hexagonal crystal family is one of the six crystal family, crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigonal crystal system and the rhombohedral lattice system are not equivalent (see section hexagonal crystal family#Crystal systems, crystal systems below). In particular, there are crystals that have trigonal symmetry but belong to the hexagonal lattice (such as α-quartz). The hexagonal crystal family consists of the 12 point groups such that at least one of their space groups has the hexagonal lattice as underlying lattice, and is the union of the hexagonal crystal system and the trigonal crystal system. There are 52 space groups associated with it, which are exactly those whose Bravais lattice is either hexagonal or rhombohedral. __TOC__ Lattice systems The hexagonal crystal family consists of two lattice systems: hexagonal and rhom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
