Sulfuric acid reaction with copper oxide

Methylpropene can be removed from the reaction mixture by distillation and easily is made the principal product by appropriate adjustment of the reaction conditions. If the 2-methylpropene is not removed as it is formed, polymer and oxidation products become important. Sulfuric acid often is an unduly strenuous reagent for dehydration of tertiary alcohols. Potassium hydrogen sulfate, copper sulfate, iodine, phosphoric acid, or phosphorus pentoxide may give better results by causing less polymerization and less oxidative degradation which, with sulfuric acid, results in the formation of sulfur dioxide. 

Dimethyl terephthalate is manufactured from terephthalic acid or directly from p-xylene. Esterification of terephthalic acid with methanol occurs with sulfuric acid as the acid catalyst. Direct oxidation of p-xylcnc with methanol present also produced dimethyl terephthalate copper salts and manganese salt are catalysts for this reaction. The dimethyl terephthalate (boiling point 288°C, melting point 141°C) must be carefully purified via a five-column distillation system. 

The decomposition of the lower sulfides of the heavy metals and the recovery of the metal as soluble salts and of sulfur in the elemental form have been demonstrated for pyrite, pyrrhotite, chalcopyrite, sphalerite, galena, molybdenite, and associated metals such as nickel and cobalt. Pyrite and chalcopyrite are higher sulfides and to be amenable to this treatment have to be thermally decomposed at 600-650 C prior to leaching. The reactions with nitric acid are exothermic, and are carried out below 1 atm and at around 100°C. In addition to the sulfides, this technique has been applied successfully to the extraction of nonferrous metals from partly oxidized sulfide ores, fayalite slags, copper scrap, and other intermediate products, such as residue from electrolytic zinc plats. 

The influence of NO on electric contact materials seems often to be due to synergistic effects with other pollutants. Whereas exposure of e.g. copper and gold contacts in an atmosphere of NO shows no corrosion effect the synergistic effect of SO and NO2 is very pronounced (, ). A possible explanation is that NO2 oxidizes SO2 to sulfuric acid according to the following reaction ... 

IRON PERSULFATE (10028-22-5) Fe2(S04)3 Light sensitive. Hygroscopic hydrolyzed slowly in water , forming acid solution and precipitates hydroxide and phosphate salts. Violent reaction with strong bases. Aqueous solution (often shipped as 73% solution) is incompatible with sulfuric acid, aluminum, caustics, alkylene oxides, ammonia, aliphatic amines, alkanolamines, amides, epichlorohydrin, organic anhydrides, isocyanates, magnesium, methyl isocyanoacetate, vinyl acetate. Corrosive to copper, copper alloys, and both mild and galvanized steel. 

TIN or TIN POWDER (7440-31-5) Sn Finely divided material is combustible and forms explosive mixture with air [autoignition temp (dust cloud) 1166°F/630°C]. Contact with moisture in 911 forms tin dioxide. A reducing agent the powder is very reactive. Violent reaction with strong acids, strong oxidizers, ammonium perchlorate, ammonium nitrate, bis-o-azido benzoyl peroxide, bromates, bromine, bromine pentafluoride, bromine trifluoride, bromine azide, cadmium, carbon tetrachloride + water, chlorine, chlorine monofluoride, chlorine nitrate, chlorine pentafluoride, chlorites, copper(II) nitrate, dimethylarsinic acid, fluorine, hydriodic acid, iodine heptafluoride, nitrosyl fluoride, oxygen difluoride, perchlorates, perchloroethylene, potassium dioxide, phosphorus pentoxide, sulfur, sulfur dichloride, turpentine (fire or explosion). 

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