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Ammonium Cyanide
Ammonium cyanide is an unstable inorganic compound with the formula NH4CN. Uses Ammonium cyanide is generally used in organic synthesis. Being unstable, it is not shipped or sold commercially. Preparation Ammonium cyanide is prepared in solution by bubbling hydrogen cyanide into aqueous ammonia at a low temperature : HCN + NH3 (aq) → NH4CN (aq) It may be prepared by the reaction of calcium cyanide and ammonium carbonate: : Ca(CN)2 + (NH4)2CO3 → 2 NH4CN + CaCO3 In dry state, ammonium cyanide is made by heating a mixture of potassium cyanide or potassium ferrocyanide with ammonium chloride and condensing the vapours into ammonium cyanide crystals: : KCN + NH4Cl → NH4CN + KCl Reactions Ammonium cyanide decomposes to ammonia and hydrogen cyanide, often forming a black polymer of hydrogen cyanide: : NH4CN → NH3 + HCN It undergoes salt metathesis reaction in solution with a number of metal salts to form metal–cyanide complexes. Reaction with ketones and aldehydes yield ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethanol
Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an Alcohol (chemistry), alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a hydroxyl group). Ethanol is a Volatility (chemistry), volatile, Combustibility and flammability, flammable, colorless liquid with a characteristic wine-like odor and pungent taste. It is a psychoactive recreational drug, the active ingredient in alcoholic drinks. Ethanol is naturally produced by the fermentation process of Carbohydrate, sugars by yeasts or via Petrochemistry, petrochemical processes such as ethylene hydration. It has medical applications as an antiseptic and disinfectant. It is used as a chemical solvent and in the Chemical synthesis, synthesis of organic compounds, and as a Alcohol fuel, fuel source. Ethanol also can be dehydrated to make ethylene, an important chemical feedstock. As of 2006, world produ ... [...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 to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titration
Titration (also known as titrimetry and volumetric analysis) is a common laboratory method of quantitative chemical analysis to determine the concentration of an identified analyte (a substance to be analyzed). A reagent, termed the ''titrant'' or ''titrator'', is prepared as a standard solution of known concentration and volume. The titrant reacts with a solution of ''analyte'' (which may also be termed the ''titrand'') to determine the analyte's concentration. The volume of titrant that reacted with the analyte is termed the ''titration volume''. History and etymology The word "titration" descends from the French word ''titrer'' (1543), meaning the proportion of gold or silver in coins or in works of gold or silver; i.e., a measure of fineness or purity. ''Tiltre'' became ''titre'', which thus came to mean the "fineness of alloyed gold", and then the "concentration of a substance in a given sample". In 1828, the French chemist Joseph Louis Gay-Lussac first used ''titre'' as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver Nitrate
Silver nitrate is an inorganic compound with chemical formula . It is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides. It was once called ''lunar caustic'' because silver was called ''luna'' by ancient alchemists who associated silver with the moon. In solid silver nitrate, the silver ions are three- coordinated in a trigonal planar arrangement. Synthesis and structure Albertus Magnus, in the 13th century, documented the ability of nitric acid to separate gold and silver by dissolving the silver. Indeed silver nitrate can be prepared by dissolving silver in nitric acid followed by evaporation of the solution. The stoichiometry of the reaction depends upon the concentration of nitric acid used. :3 Ag + 4 HNO3 (cold and diluted) → 3 AgNO3 + 2 H2O + NO :Ag + 2 HNO3 (hot and concentrated) → AgNO3 + H2O + NO2 The structure of silver nitrate has been examined by X-ray crystallography sever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strecker Amino Acid Synthesis
The Strecker amino acid synthesis, also known simply as the Strecker synthesis, is a method for the synthesis of amino acids by the reaction of an aldehyde with ammonia in the presence of potassium cyanide. The condensation reaction yields an α-aminonitrile, which is subsequently hydrolyzed to give the desired amino acid. The method is used commercially for the production of racemic methionine from methional. While usage of ammonium salts gives unsubstituted amino acids, primary and secondary amines also give substituted amino acids. Likewise, the usage of ketones, instead of aldehydes, gives α,α-disubstituted amino acids. Reaction mechanism In the first part of the reaction, the carbonyl oxygen of an aldehyde is protonated, followed by a nucleophilic attack of ammonia to the carbonyl carbon. After subsequent proton exchange, water is cleaved from the iminium ion intermediate. A cyanide ion then attacks the iminium carbon yielding an aminonitrile. In the second part of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aldehyde
In organic chemistry, an aldehyde () 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 common and play important roles in the technology and biological spheres. Structure and bonding Aldehydes feature a carbon center that is connected by a double bond to oxygen and a single bond to hydrogen and 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 C=O 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 are more soluble in water, formaldehyde and acetaldehyde completely so. The volatile aldehydes have pungent odors. Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketone
In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double bond C=O). The simplest ketone is acetone (where R and R' is methyl), with the formula . Many ketones are of great importance in biology and in 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 considere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt Metathesis Reaction
A salt metathesis reaction, sometimes called a double displacement reaction, is a chemical process involving the exchange of bonds between two reacting chemical species which results in the creation of products with similar or identical bonding affiliations. This reaction is represented by the general scheme: :AB + CD -> AD + CB The bond between the reacting species can be either ionic or covalent. Classically, these reactions result in the precipitation of one product. In older literature, the term double decomposition is frequently encountered. The term double decomposition is more specifically used when at least one of the substances does not dissolve in the solvent, as the ligand or ion exchange takes place in the solid state of the reactant. For example: :AX(aq) + BY(s) → AY(aq) + BX(s). Types of reactions Counterion exchange Salt metathesis is a common technique for exchanging counterions. The choice of reactants is guided by a solubility chart or lattice energy. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Ferrocyanide
Potassium ferrocyanide is the inorganic compound with formula K4 e(CN)6·3H2O. It is the potassium salt of the coordination complex e(CN)6sup>4−. This salt forms lemon-yellow monoclinic crystals. Synthesis In 1752, the French chemist Pierre Joseph Macquer (1718–1784) first reported the preparation of potassium ferrocyanide, which he achieved by reacting Prussian blue (iron(III) ferrocyanide) with potassium hydroxide. Modern production Potassium ferrocyanide is produced industrially from hydrogen cyanide, ferrous chloride, and calcium hydroxide, the combination of which affords Ca2 e(CN)6·11H2O. This solution is then treated with potassium salts to precipitate the mixed calcium-potassium salt CaK2 e(CN)6 which in turn is treated with potassium carbonate to give the tetrapotassium salt. Historical production Historically, the compound was manufactured from organic compounds containing nitrogen, iron filings, and potassium carbonate. Common nitrogen and carbon sources wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonium Carbonate
Ammonium carbonate is a salt with the chemical formula (NH4)2CO3. Since it readily degrades to gaseous ammonia and carbon dioxide upon heating, it is used as a leavening agent and also as smelling salt. It is also known as baker's ammonia and is a predecessor to the more modern leavening agents baking soda and baking powder. It is a component of what was formerly known as sal volatile and salt of hartshorn, and produces a pungent smell when baked. Production Ammonium carbonate is produced by combining carbon dioxide and aqueous ammonia. About 80,000 tons/year were produced as of 1997. An orthorhombic monohydrate is known. It crystallizes in an ammonia solution exposed in a carbon dioxide-rich atmosphere. Decomposition Ammonium carbonate slowly decomposes at standard temperature and pressure through two pathways. Thus any initially pure sample of ammonium carbonate will soon become a mixture including various byproducts. Ammonium carbonate can spontaneously decompose into ammo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
