Ammonium molybdates chromate

Several gas detector tubes are used in conjunction with common colorimetric reactions to detect butadiene. The reactions include the reduction of chromate or dichromate to chromous ion and the reduction of ammonium molybdate and palladium sulfate to molybdemun blue (Saltzman Harman, 1989). 

Molybdenum salts used as catalysts include cobalt molybdate for hydrogen treatment of petroleum stocks for desulfurization, and phospho-molybdates to promote oxidation. Compounds used for dyes are sodium, potassium, and ammonium molybdates. With basic dyes, phosphomolyb-dic acid is employed. The pigment known as molybdenum orange is a mixed crystal of lead chromate and lead molybdate. Sodium molybdate, or molybdic oxide, is added to fertilizers as a beneficial trace element. Zinc and calcium molybdate serve as inhibitory pigments in protective coatings arid paint for metals subjected to a corrosive atmosphere. Compounds used to produce better adherence of enamels are molybdenum trioxide and ammonium, sodium, calcium, barium, and lead molybdates. 

It is precipitated by potassium chromate, ferricyanide, bismuthi-iodide, and mercuri-iodide, ammonium molybdate, platinic chloride, and auric chloride [1]. 

The effects of ammonium chromate, ammonium dichromate, ammonium molybdate, and ammonium tungstate as additives on the catalytic performance of rhodium catalysts for the hydroformylation of Cg-oleftns and 1-dodecene were investigated. Modification of the rhodium catalyst with ammonium salts resulted in moderate increase in aldehyde yields and decrease in rhodium losses in the distillation process for the separation of products from the catalyst [11]. 

Arsenites may also be determined by this procedure but must first be oxidised by treatment with nitric acid. Small amounts of antimony and tin do not interfere, but chromates, phosphates, molybdates, tungstates, and vanadates, which precipitate as the silver salts, should be absent. An excessive amount of ammonium salts has a solvent action on the silver arsenate. 

H. Stamm also measured the solubilities of the salts of the alkalies in liquid ammonia —potassium hydroxide, nitrate, sulphate, chromate, oxalate, perchlorate, persulphate, chloride, bromide, iodide, carbonate, and chlorate rubidium chloride, bromide, and sulphate esesium chloride, iodide, carbonate, and sulphate lithium chloride and sulphate sodium phosphate, phosphite, hypophosphite, fluoride, chloride, iodide, bromate, perchlorate, periodate, hyponitrire, nitrite, nitrate, azide, dithionate, chromate, carbonate, oxalate, benzoate, phtnalate, isophthalate ammonium, chloride, chlorate, bromide, iodide, perchlorate, sulphate, sulphite, chromate, molybdate, nitrate, dithionate, thiosulphate, persulphate, thiocyanate, phosphate, phosphite, hypophosphite, arsenate, arsenite, amidosulphonate, ferrocyanide, carbonate, benzoate, methionate, phenylacetate, picrate, salicylate, phenylpropionate, benzoldisulphonate, benzolsulphonate, phthalate, trimesmate, mellitate, aliphatic dicarboxylates, tartrate, fumarate, and maleinate and phenol. 

Some chemicals that are reported to stimulate glowing are chromates, molybdates, halides of chromium, manganese, cobalt and copper, and ferric and stannic oxides (.5,10) Chemicals found to be ineffective in retarding afterglow in a limited study were ammonium sulfate and sodium borates (10). ... 

Defined as those containing only the simple MO ions, they can be obtained from solutions of M03 in aqueous alkali. The MO ions persist as such in basic solution. Although both molybdates and tungstates can be reduced in solution (see later), they lack the powerful oxidizing property so characteristic of chromates(VI). The normal tungstates and molybdates of many other metals can be prepared by meta-thetical reactions. The alkali metal, ammonium, magnesium, and thallous salts are soluble in water, whereas those of other metals are nearly all insoluble. 

One of the simplest methods of preparation is by decomposition of a thermally unstable compound. The nitrate or chloride is often preferred, sulphates tend to decompose at higher temperatures. Where the presence of residual traces of anion is to be avoided, the metal salts of organic acids are particularly useful. Formates, oxalates, acetates etc, decompose at low temperatures and often reduce the metal at the same time. For the preparation of catalysts from anions, the ammonium salt is frequently used. Metallic salts of complex acids can be used as a source of metal oxide mixtures. Decomposition of the appropriate chromate, tungstate, molybdate or vanadate will produce the mixed oxide. 

Because the decompositions of many ammonium salts evolve NHj and HjO simultaneously (or conseeutively) in a 2 1 molar ratio, it is often convenient to represent the formula of such salts in the form m(NH4)20.n(metal oxide).xH20, where m, n and x are integers (see ammonium chromates, vanadates, tungstates and molybdates below). 

Inorganic anodic and mixed Cl present water-soluble salts of ammonium, alkali (sodium, potassium), alkaline-earth (calcium, strontium, magnesium, barium) and other (zinc, lead) metals containing active anions in their molecules (nitrates, nitrites, chromates, carbonates, phosphates, molybdates, silicates). ... 

Ammonium dimolybdate corrosion inhibitor, vapor-phase Dicyclohexylamine nitrite 2-Dimethylamino-2-methyl-1-propanol corrosion inhibitor, waterfloods Cocodiamine acetate Etidronic acid corrosion inhibitor, water systems Acrylic resin Hydrazine corrosion inhibitor, water treatment Ammonium dimolybdate Calcium oxide Etidronic acid Lauramine 2-Mercaptobenzothiazole Myristamine Myristamine acetate PEG-8 dioleate PEG-3 tallow aminopropylamine PEG-8 tallow aminopropylamine Potassium phosphate Potassium thiocyanate Potassium tripolyphosphate Sodium chromate Sodium molybdate dihydrate... 

Cupric sulfate anhydrous Cupric sulfate pentahydrate Direct brown 95 Ferric ammonium ferrocyanide Ferric chloride Ferric chloride hexahydrate Ferric sulfate Lead chromate oxide Lead molybdate Mercury sulfide (ic), black Mercury sulfide (ic), red Molybdenum trioxide 3-Naphthol Nonoxynol-55 Phosphomolybdic acid... 

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