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Zirconium Hydroxide
Zirconium (IV) hydroxide, often called hydrous zirconia is an ill-defined material or family of materials variously described as and . All are white solids with low solubility in water. These materials are widely employed in the preparation of solid acid catalysts. These materials are generated by mild base hydrolysis of zirconium halides and nitrates. A typical precursor is zirconium oxychloride Zirconyl chloride is the inorganic compound with the formula of r4(OH)8(H2O)16l8(H2O)12, more commonly written ZrOCl2·8H2O, and referred to as zirconyl chloride octahydrate. It is a white solid and is the most common water-soluble derivative of .... References External links * Hydroxides Zirconium(IV) compounds {{inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid Acid Catalyst
In acid catalysis and base catalysis, a chemical reaction is catalyzed by an acid or a base. By Brønsted–Lowry acid–base theory, the acid is the proton (hydrogen ion, H+) donor and the base is the proton acceptor. Typical reactions catalyzed by proton transfer are esterifications and aldol reactions. In these reactions, the conjugate acid of the carbonyl group is a better electrophile than the neutral carbonyl group itself. Depending on the chemical species that act as the acid or base, catalytic mechanisms can be classified as either specific catalysis and general catalysis. Many enzymes operate by general catalysis. Applications and examples Brønsted acids Acid catalysis is mainly used for organic chemical reactions. Many acids can function as sources for the protons. Acid used for acid catalysis include hydrofluoric acid (in the alkylation process), phosphoric acid, toluenesulfonic acid, polystyrene sulfonate, heteropoly acids, zeolites. Strong acids catalyze the hydr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zirconium
Zirconium is a chemical element with the symbol Zr and atomic number 40. The name ''zirconium'' is taken from the name of the mineral zircon, the most important source of zirconium. The word is related to Persian '' zargun'' (zircon; ''zar-gun'', "gold-like" or "as gold"). It is a lustrous, grey-white, strong transition metal that closely resembles hafnium and, to a lesser extent, titanium. Zirconium is mainly used as a refractory and opacifier, although small amounts are used as an alloying agent for its strong resistance to corrosion. Zirconium forms a variety of inorganic and organometallic compounds such as zirconium dioxide and zirconocene dichloride, respectively. Five isotopes occur naturally, four of which are stable. Zirconium compounds have no known biological role. Characteristics Zirconium is a lustrous, greyish-white, soft, ductile, malleable metal that is solid at room temperature, though it is hard and brittle at lesser purities. In powder form, zirconium is highl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halide
In chemistry, a halide (rarely halogenide) is a binary chemical compound, of which one part is a halogen atom and the other part is an element or radical that is less electronegative (or more electropositive) than the halogen, to make a fluoride, chloride, bromide, iodide, astatide, or theoretically tennesside compound. The alkali metals combine directly with halogens under appropriate conditions forming halides of the general formula, MX (X = F, Cl, Br or I). Many salts are halides; the ''hal-'' syllable in ''halide'' and ''halite'' reflects this correlation. All Group 1 metals form halides that are white solids at room temperature. A halide ion is a halogen atom bearing a negative charge. The halide anions are fluoride (), chloride (), bromide (), iodide () and astatide (). Such ions are present in all ionic halide salts. Halide minerals contain halides. All these halides are colourless, high melting crystalline solids having high negative enthalpies of formation. Test ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zirconium Oxychloride
Zirconyl chloride is the inorganic compound with the formula of r4(OH)8(H2O)16l8(H2O)12, more commonly written ZrOCl2·8H2O, and referred to as zirconyl chloride octahydrate. It is a white solid and is the most common water-soluble derivative of zirconium. A compound with the formula ZrOCl2 has not been characterized. Production and structure and zirconyl chloride. The salt is produced by hydrolysis of zirconium tetrachloride or treating zirconium oxide with hydrochloric acid.Ralph Nielsen "Zirconium and Zirconium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. It adopts a tetrameric structure, consisting of the cation r4(OH)8sup>8+. features four pairs of hydroxide bridging ligands linking four Zr4+ centers. The chloride anions are not ligands, consistent with the high oxophilicity of Zr(IV). The salt crystallizes as tetragonal crystals.T. W. Mak "Refinement of the crystal structure of zirconyl chloride octahydrate" Canadian Journa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxides
Hydroxide is a polyatomic ion, diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually Self-ionization of water, minor constituent of water. It functions as a base (chemistry), base, a ligand, a nucleophile, and a catalyst. The hydroxide ion forms salt (chemistry), salts, some of which dissociation (chemistry), dissociate in aqueous solution, liberating solvated hydroxide ions. Sodium hydroxide is a multi-million-ton per annum commodity chemicals, commodity chemical. The corresponding electrically neutral compound HO• is the hydroxyl radical. The corresponding covalent bond, covalently bound functional group, group –OH of atoms is the hydroxy group. Both the hydroxide ion and hydroxy group are nucleophiles and can act as catalysts in organic chemistry. Many inorganic substances which bear the word ''hydroxide'' in their names ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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