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Cyanides
Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms. In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of a carbon atom triple-bonded to a nitrogen atom. In inorganic cyanides, the cyanide group is present as the anion . Soluble salts such as sodium cyanide (NaCN) and potassium cyanide (KCN) are highly toxic. Hydrocyanic acid, also known as hydrogen cyanide, or HCN, is a highly volatile liquid that is produced on a large scale industrially. It is obtained by acidification of cyanide salts. Organic cyanides are usually called nitriles. In nitriles, the group is linked by a covalent bond to carbon. For example, in acetonitrile (), the cyanide group is bonded to methyl (). Although nitriles generally do not release cyanide ions, the cyanohydrins do and are thus rather toxic. Bonding The cyanide ion is isoelectronic with carbon monoxide and wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Cyanide
Sodium cyanide is a poisonous compound with the formula Na C N. It is a white, water-soluble solid. Cyanide has a high affinity for metals, which leads to the high toxicity of this salt. Its main application, in gold mining, also exploits its high reactivity toward metals. It is a moderately strong base. Production and chemical properties Sodium cyanide is produced by treating hydrogen cyanide with sodium hydroxide: :HCN + NaOH → NaCN + H2O Worldwide production was estimated at 500,000 tons in the year 2006. Formerly it was prepared by the Castner process involving the reaction of sodium amide with carbon at elevated temperatures. : NaNH2 + C → NaCN + H2 The structure of solid NaCN is related to that of sodium chloride. The anions and cations are each six-coordinate. Potassium cyanide (KCN) adopts a similar structure. When treated with acid, it forms the toxic gas hydrogen cyanide: : NaCN + H+ → HCN + Na+ Because the salt is derived from a weak acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Cyanide
Potassium cyanide is a compound with the formula KCN. This colorless crystalline salt, similar in appearance to sugar, is highly soluble in water. Most KCN is used in gold mining, organic synthesis, and electroplating. Smaller applications include jewellery for chemical gilding and buffing.Andreas Rubo, Raf Kellens, Jay Reddy, Joshua Wooten, Wolfgang Hasenpusch "Alkali Metal Cyanides" in Ullmann's Encyclopedia of Industrial Chemistry 2006 Wiley-VCH, Weinheim, Germany. Potassium cyanide is highly toxic. The moist solid emits small amounts of hydrogen cyanide due to hydrolysis, which may smell like bitter almonds. Not everyone, however, can smell cyanide; the ability to do so is a genetic trait. The taste of potassium cyanide has been described as acrid and bitter, with a burning sensation similar to lye. Production KCN is produced by treating hydrogen cyanide with an aqueous solution of potassium hydroxide, followed by evaporation of the solution in a vacuum: About 50,000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Cyanide
Hydrogen cyanide, sometimes called prussic acid, is a chemical compound with the formula HCN and structure . It is a colorless, extremely poisonous, and flammable liquid that boils slightly above room temperature, at . HCN is produced on an industrial scale and is a highly valued precursor to many chemical compounds ranging from polymers to pharmaceuticals. Large-scale applications are for the production of potassium cyanide and adiponitrile, used in mining and plastics, respectively. It is more toxic than solid cyanide compounds due to its volatile nature. Structure and general properties Hydrogen cyanide is a linear molecule, with a triple bond between carbon and nitrogen. The tautomer of HCN is HNC, hydrogen isocyanide. Hydrogen cyanide is weakly acidic with a p''K''a of 9.2. It partially ionizes in water solution to give the cyanide anion, CN−. A solution of hydrogen cyanide in water, represented as HCN, is called ''hydrocyanic acid''. The salts of the cyanid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrocyanic Acid
Hydrogen cyanide, sometimes called prussic acid, is a chemical compound with the formula HCN and structure . It is a colorless, extremely poisonous, and flammable liquid that boils slightly above room temperature, at . HCN is produced on an industrial scale and is a highly valued precursor to many chemical compounds ranging from polymers to pharmaceuticals. Large-scale applications are for the production of potassium cyanide and adiponitrile, used in mining and plastics, respectively. It is more toxic than solid cyanide compounds due to its volatile nature. Structure and general properties Hydrogen cyanide is a linear molecule, with a triple bond between carbon and nitrogen. The tautomer of HCN is HNC, hydrogen isocyanide. Hydrogen cyanide is weakly acidic with a p''K''a of 9.2. It partially ionizes in water solution to give the cyanide anion, CN−. A solution of hydrogen cyanide in water, represented as HCN, is called ''hydrocyanic acid''. The salts of the cyanide anio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrile
In organic chemistry, a nitrile is any organic compound that has a functional group. The prefix '' cyano-'' is used interchangeably with the term ''nitrile'' in industrial literature. Nitriles are found in many useful compounds, including methyl cyanoacrylate, used in super glue, and nitrile rubber, a nitrile-containing polymer used in latex-free laboratory and medical gloves. Nitrile rubber is also widely used as automotive and other seals since it is resistant to fuels and oils. Organic compounds containing multiple nitrile groups are known as cyanocarbons. Inorganic compounds containing the group are not called nitriles, but cyanides instead. Though both nitriles and cyanides can be derived from cyanide salts, most nitriles are not nearly as toxic. Structure and basic properties The N−C−C geometry is linear in nitriles, reflecting the sp hybridization of the triply bonded carbon. The C−N distance is short at 1.16 Å, consistent with a triple bond. Nitr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prussian Blue
Prussian blue (also known as Berlin blue, Brandenburg blue or, in painting, Parisian or Paris blue) is a dark blue pigment produced by oxidation of ferrous ferrocyanide salts. It has the chemical formula Fe CN)">Cyanide.html" ;"title="e(Cyanide">CN) Turnbull's blue is chemically identical, but is made from different reagents, and its slightly different color stems from different impurities and particle sizes. Prussian blue was the first modern synthetic pigment. It is prepared as a very fine colloidal dispersion, because the compound is not soluble in water. It contains variable amounts of other ions and its appearance depends sensitively on the size of the colloidal particles. The pigment is used in paints, and it is the traditional "blue" in blueprints, and became prominent in 19th-century () Japanese woodblock prints. In medicine, orally administered Prussian blue is used as an antidote for certain kinds of heavy metal poisoning, e.g., by thallium(I) and radioactive ... [...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 carbon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanohydrin
In organic chemistry, a cyanohydrin or hydroxynitrile is a functional group found in organic compounds in which a cyano and a hydroxy group are attached to the same carbon atom. The general formula is , where R is H, alkyl, or aryl. Cyanohydrins are industrially important precursors to carboxylic acids and some amino acids. Cyanohydrins can be formed by the cyanohydrin reaction, which involves treating a ketone or an aldehyde with hydrogen cyanide (HCN) in the presence of excess amounts of sodium cyanide (NaCN) as a catalyst: : In this reaction, the nucleophilic ion attacks the electrophilic carbonyl carbon in the ketone, followed by protonation by HCN, thereby regenerating the cyanide anion. Cyanohydrins are also prepared by displacement of sulfite by cyanide salts: : Cyanohydrins are intermediates in the Strecker amino acid synthesis. In aqueous acid, they are hydrolyzed to the α-hydroxy acid. Acetone cyanohydrins Acetone cyanohydrin, (CH3)2C(OH)CN is the cya ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus '' Malus''. The tree originated in Central Asia, where its wild ancestor, '' Malus sieversii'', is still found today. Apples have been grown for thousands of years in Asia and Europe and were brought to North America by European colonists. Apples have religious and mythological significance in many cultures, including Norse, Greek, and European Christian tradition. Apples grown from seed tend to be very different from those of their parents, and the resultant fruit frequently lacks desired characteristics. Generally, apple cultivars are propagated by clonal grafting onto rootstocks. Apple trees grown without rootstocks tend to be larger and much slower to fruit after planting. Rootstocks are used to control the speed of growth and the size of the resulting tree, allowing for easier harvesting. Ther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apricot
An apricot (, ) is a fruit, or the tree that bears the fruit, of several species in the genus '' Prunus''. Usually, an apricot is from the species '' P. armeniaca'', but the fruits of the other species in ''Prunus'' sect. ''Armeniaca'' are also called apricots. Etymology ''Apricot'' first appeared in English in the 16th century as ''abrecock'' from the Middle French ''aubercot'' or later ''abricot'', from Spanish '' albaricoque'' and Catalan ''a(l)bercoc'', in turn from Arabic الْبَرْقُوق (al-barqūq, "the plums"), from Byzantine Greek βερικοκκίᾱ (berikokkíā, "apricot tree"), derived from late Greek ''πραικόκιον'' (''praikókion'', "apricot") from Latin '' ersica ("peach")praecocia'' (''praecoquus'', "early ripening"). Species Apricots are species belonging to ''Prunus'' sect. ''Armeniaca''. The taxonomic position of '' P. brigantina'' is disputed. It is grouped with plum species according to chloroplast DNA sequences, but more closel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bitter Almond
The almond (''Prunus amygdalus'', syn. ''Prunus dulcis'') is a species of tree native to Iran and surrounding countries, including the Levant. The almond is also the name of the edible and widely cultivated seed of this tree. Within the genus ''Prunus'', it is classified with the peach in the subgenus ''Amygdalus'', distinguished from the other subgenera by corrugations on the shell (endocarp) surrounding the seed. The fruit of the almond is a drupe, consisting of an outer hull and a hard shell with the seed, which is not a true nut. ''Shelling'' almonds refers to removing the shell to reveal the seed. Almonds are sold shelled or unshelled. Blanched almonds are shelled almonds that have been treated with hot water to soften the seedcoat, which is then removed to reveal the white embryo. Once almonds are cleaned and processed, they can be stored over time. Almonds are used in many food cuisines, often featuring prominently in desserts, such as marzipan. The almond tree prosp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antifeedant
Antifeedants are organic compounds produced by plants to inhibit attack by insects and grazing animals. These chemical compounds are typically classified as secondary metabolites in that they are not essential for the metabolism of the plant, but instead confer longevity. Antifeedants exhibit a wide range of activities and chemical structures as biopesticides. Examples include rosin, which inhibits attack on trees, and many alkaloids, which are highly toxic to specific insect species. History "Plant-derived insecticides (e.g., rotenone, veratridines, pyrethrins, and nicotine) have been used for insect control since antiquity." The active ingredients in these plants have been purified and modified. For example, variations on pyrethrin has spawned a large number of synthetic insecticides call pyrethroids. Culinary implications In addition to their role defending the plant, antifeedants often confer taste or odors, enhancing the flavor of certain plants. Examples are provided ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
