Silver monoxide

Silver hypochlorite, AgOCl.—A very unstable solution of the hypochlorite is formed by the action of chlorine-water on excess of silver monoxide. It soon decomposes into silver chloride and chlorate. 

Silver monoxide, AgaO.—Addition of the hydroxide of barium or of an alkali-metal to silver-nitrate solution precipitates the monoxide as a blackish, amorphous powder, which crystallizes from ammoniacal solution in violet crystals. Its density is given as 7-143 and 7-250. Ammoniacal silver oxide has been known to explode, the phenomenon being probably due to the formation of fulminating silver (compare p. 315).4... 

Silver monoxide dissolves in water, forming an alkaline solution which turns red litmus blue. At 25° C. its solubility corresponds with 2-16 xlO-4 gram-molecule per litre of water,6 and at 15° C. Rebi re 7 found the same value. It is a strong base, its salts having a neutral reaction. The solution is coloured reddish and decomposed by the action of light, the change being possibly attended by deposition of the suboxide or of colloidal silver. 

Argentic oxide, AgO.—A hot alkaline solution of potassium permanganate partially oxidizes silver monoxide to argentic oxide 13... 

Berthollet s fulminating silver is produced by addition of alcohol to a concentrated solution of silver monoxide in ammonium hydroxide. It forms small, black crystals, exploded by friction, and soluble in potassium-cyanide solution. It probably has the formula NAgs or NAgH2 2 and it has no connexion with silver fulminate, C.-N.O.Ag. 

Silver nitrate, AgN03.—Silver, silver monoxide, silver sulphide, and silver carbonate dissolve in nitric acid. Concentration of the solutions yields colourless, rhombic crystals of silver nitrate, of melting-point 208-6° C., and density 4-3554. It is characterized by its caustic action on the skin, its power of blackening it, its antiseptic properties, and its metallic taste. 

Silver borate, AgB02.—A solution of borax reacts with one of silver nitrate to precipitate the white metaborate, AgB02. It is also produced by dissolving silver monoxide in boric acid, an equilibrium being attained. Conversely, water causes partial hydrolysis of silver borate to silver monoxide and boric acid.6... 

Silver oxide 4076 Ag20 Argentic oxide protoxide of stiver silver monoxide. Silver sand A hard, heavy, silver-colored sand used by lithographers for rubbing stones to a level surface. 

Silver monoxid—Protoxid—Argenti oxidum—(V. S. Br.)— AgaO —231.8—formed by precipitating a solution of silver nitrate with... 

Steimle, T., Tanimoto, M., Namiki, K., Saito, S. The millimeter wave spectrum of silver monoxide, AgO, J. Chem. Phys. 108 (1998) 7616-7622. 

Carey Lea silver Cargon monoxide Cargutoan Cariflex Carlisle... 

In contrast to the silver process, all of the formaldehyde is made by the exothermic reaction (eq. 23) at essentially atmospheric pressure and at 300—400°C. By proper temperature control, a methanol conversion greater than 99% can be maintained. By-products are carbon monoxide and dimethyl ether, in addition to small amounts of carbon dioxide and formic acid. Overall plant yields are 88—92%. 

Nickel [7440-02-0] Ni, recognized as an element as early as 1754 (1), was not isolated until 1820 (2). It was mined from arsenic sulfide mineral deposits (3) and first used in an alloy called German Silver (4). Soon after, nickel was used as an anode in solutions of nickel sulfate [7786-81 A] NiSO, and nickel chloride [7718-54-9] NiCl, to electroplate jewelry. Nickel carbonyl [13463-39-3] Ni(C02)4, was discovered in 1890 (see Carbonyls). This material, distilled as a hquid, decomposes into carbon monoxide and pure nickel powder, a method used in nickel refining (5) (see Nickel and nickel alloys). 

Silver sulfate decomposes above 1085°C into silver, sulfur dioxide, and oxygen. This property is utilized ia the separation of silver from sulfide ores by direct oxidation. Silver sulfate is reduced to silver metal by hydrogen, carbon, carbon monoxide, zinc, and copper. 

Thin films of photochromic glass containing silver haUde have been produced by simultaneous vacuum deposition of siUcon monoxide, lead siUcate, aluminum chloride, copper (I) chloride, and silver haUdes (9). Again, heat treatment (120°C for several hours) after vacuum deposition results in the formation of photochromic silver haUde crystaUites. Photochemical darkening and thermal fade rates are much slower than those of the standard dispersed systems. 

Determination of oxygen. The sample is weighed into a silver container which has been solvent-washed, dried at 400 °C and kept in a closed container to avoid oxidation. It is dropped into a reactor heated at 1060 °C, quantitative conversion of oxygen to carbon monoxide being achieved by a layer of nickel-coated carbon (see Note). The pyrolysis gases then flow into the chromatographic column (1 m long) of molecular sieves (5 x 10-8 cm) heated at 100 °C the CO is separated from N2, CH4, and H2, and is measured by a thermal conductivity detector. 

The most successful class of active ingredient for both oxidation and reduction is that of the noble metals silver, gold, ruthenium, rhodium, palladium, osmium, iridium, and platinum. Platinum and palladium readily oxidize carbon monoxide, all the hydrocarbons except methane, and the partially oxygenated organic compounds such as aldehydes and alcohols. Under reducing conditions, platinum can convert NO to N2 and to NH3. Platinum and palladium are used in small quantities as promoters for less active base metal oxide catalysts. Platinum is also a candidate for simultaneous oxidation and reduction when the oxidant/re-ductant ratio is within 1% of stoichiometry. The other four elements of the platinum family are in short supply. Ruthenium produces the least NH3 concentration in NO reduction in comparison with other catalysts, but it forms volatile toxic oxides. 

Ethylene is selectively oxidized to ethylene oxide using a silver-based catalyst in a fixed-bed reactor. Ethylene and oxygen are supplied from the gas phase and ethylene oxide is removed by it. The catalyst is stationary. Undesired, kinetically determined by-products include carbon monoxide and water. Ideally, a pure reactant is converted to one product with no by-products. 

Soma-Noto Y, Sachtler WMH. 1974. Infrared spectra of carbon monoxide adsorbed on supported palladium and palladium-silver alloys, J Catal 32 315. 

Cuesta A, Lopez N, Gutierrez C. 2003. Electrolyte electroreflectance study of carbon monoxide adsorption on polycrystalline silver and gold electrodes. Electrochim Acta 48 2949-2956. Date M, Hamta M. 2001. Moisture effect on CO oxidation over Au/Ti02 catalyst. J Catal 201 221-224. 

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