Sulfuric acid, reactions

Sulfonation of castor oil using anhydrous SO yields a product having better hydrolytic stabiUty than that from the sulfuric acid reaction. The organically combined SO is low compared to the amount of SO introduced to the reaction the final product contains only 8.0—8.5 wt % combined SO although 17 wt % SO is added. The product contains less inorganic salts and free fatty acids than the sulfuric acid product (36). 

Hibbert and Burt dissolved the benzoylperoxide in dry ether, cooled to — 50 and added the calculated amount of a 10 per cent sodium ethylate solution, maintaining the low temperature during the procedure. Sufficient ice water was added to give a clear solution, the ether containing the ethyl benzoate separated and the aqueous sodium benzoylperoxide solution added slowly with stirring to twice the necessary amount of cold 20 per cent sulfuric acid (reaction mixture always at o°). The oily layer of benzoylhydroperoxide was then extracted three times with chloroform and the extract dried over anhydrous sodium sulfate. 

The acid is prepared by sulfonation of nitrobenzene with oleum, and the reaction product consists essentially of a hot solution of the acid in sulfuric acid. A completed 270 1 batch exploded violently after hot storage at 150C for several hours. An exotherm develops at 145°C, and the acid is known to decompose at 200 C [ 1], A similar incident arose from water leaking from a cooling coil into the fuming sulfuric acid reaction medium, which caused an exotherm to over 150°C and subsequent violent decomposition [2], Detailed examination of the thermal decomposition of the acid shows that it is much slower for the isolated acid than for the reaction mass, and that the concentration of sulfur trioxide in the oleum used for sulfonation bears... 

Thermal decomposition of sulfuric acid, reaction 4.1, proceeds in the following two steps ... 

Europeum generally is produced from two common rare earth minerals monazite, a rare earth-thorium orthophosphate, and bastnasite, a rare earth fluocarbonate. The ores are crushed and subjected to flotation. They are opened by sulfuric acid. Reaction with concentrated sulfuric acid at a temperature between 130 to 170°C converts thorium and the rare earths to their hydrous sulfates. The reaction is exothermic which raises the temperature to 250°C. The product sulfates are treated with cold water which dissolves the thorium and rare earth sulfates. The solution is then treated with sodium sulfate which precipitates rare earth elements by forming rare earth-sodium double salts. The precipitate is heated with sodium hydroxide to obtain rare earth hydrated oxides. Upon heating and drying, cerium hydrated oxide oxidizes to tetravalent ceric(lV) hydroxide. When the hydrated oxides are treated with hydrochloric acid or nitric acid, aU but Ce4+ salt dissolves in the acid. The insoluble Ce4+ salt is removed. 

Method 2 (phenol-sulfuric acid reaction). The reaction of carbohydrates with phenol in the presence of sulfuric acid produces a UV-absorbing chromophore which is sufficiently sensitive to be used as a means of detecting less than 1-pg amounts of carbohydrates... 

The fuming sulfuric acid reaction of adamantane followed by chromic acid oxidation has also been found to produce small amounts of 92 (Eq. (77)) which may be isolated by column chromatography 289). 

Fig. 9.1. Single contact H2SO4 making flowsheet. SO3 rich gas from catalytic SO2 oxidation is reacted with strong sulfuric acid, Reaction (1.2). The reaction consumes H20(f) and makes H2S04(f), strengthening the acid. Double contact H2SO4 making is described in Fig. 9.6. A few plants lower the SO2 content of their tail gas by scrubbing the gas with basic solution (Hay et al., 2003).

This is a new reaction for the preparation of N-alkyl amides. Nitriles and various substituted cyano compounds are treated with active olefins in the presence of sulfuric acid. Reaction occurs at room temperature in glacial acetic acid or dibutyl ether solution. The use of hydrogen cyanide in the reaction leads to the formation of N-alkylformamides. /-Butyl alcohol and sodium cyanide are used in place of the olefin and hydrogen cyanide in the preparation of N-/-butylfotmamide (50%). The reaction has been extended to the synthesis of N-alkyl diamides from dinitriles and olefins or alcohols. ... 

The driving force of this reaction as expressed by the change of free enthalpy is -106.32 kcal/mole = -444.84 kJ/mole, which is a gigantic value, giving this reaction a huge thermodynamic preference over the competitive sulfuric acid reaction... 

---