Gradual decomposition

AH the bis- and tri-unsaturated prostanoids display sensitivity to atmospheric oxygen similar to that of polyunsaturated fatty acids and Hpids. As a result, exposure to the air causes gradual decomposition although the crystalline prostanoids ate less prone to oxygenation reactions than PG oils or solutions. 

In this way one avoids an excess of hydrochloric acid which, if it adheres to the product, causes its gradual decomposition. 

Melting points determined in the ordinary way are unsatisfactory because gradual decomposition occurs over a broad tern-... 

The product is air stable in the solid state. In solution gradual decomposition sets in after 2 to 3 days. 

At last, the examination of an eye bum patient aims to search and eliminate any concretion, particularly at the level of the conjunctival sacs. These concretions may help a continuation of the bum, because they are due to precipitations of either the chemical (for instance, lime) or dust projected with the chemical. These concretions result in the gradual decomposition of the compound at the level of the eye. 

The system ammonium nitrate, aluminium, nitro compound (e.g. TNT) would be expected to undergo gradual decomposition, e.g. that in stored shells and bombs filled with such mixtures changes would occur, leading to the oxidation of the aluminium. Obviously, a mixture containing oxidized aluminium has lower explosive power than the same mixture containing metallic aluminium. It was therefore very important to determine the mechanism of the oxidation of aluminium. It became apparent that this is caused by impurities in the ammonium nitrate, not by the... 

Under suitable conditions, certain chemical reactions will give rise to nacreous sulphur the most satisfactory result is obtained by allowing slow inter-diffusion of solutions of sodium thiosulphate and potassium hydrogen sulphate to occur.7 Another method involves the gradual decomposition of sulphur chloride or bromide by the vapour of water or methyl alcohol at the ordinary temperature.8 The decomposition of calcium polysulphidcs by hydrochloric acid,9 and of hydrogen persulphide by the addition of alcohol, ether, ethyl acetate or other organic solvents, also yields sulphur of the desired modification. 

When submitted, in a glass vessel, to the electric spark discharge, or when heated to 400° C., gradual decomposition sets in, with formation of sulphur dioxide and fluorine, the latter giving rise to silicon tetrafluoride, and the total change being representable by the equation ... 

Sulphur and phosphorus do not affect the fluoride even at 500° C., but hot sodium causes gradual decomposition, with complete absorption. 

It attacks glass at a red heat, giving silicon tetrafluoride and sulphur trioxide. Carbon and boron are without action on the gas at a red heat, but sodium at a temperature considerably above the melting-point causes gradual decomposition with absorption. Hydrogen sulphide, aided by heat, attacks both thionyl and sulphuryl fluorides, inducing decomposition.1... 

Hydrogen sulphide in excess causes gradual decomposition, sulphur... 

The monochloride is soluble in various inert organic liquids, more particularly in benzene, chloroform, carbon tetrachloride and carbon disulphide, without undergoing chemical change. It is an exothermic compound, its heat of formation from gaseous chlorine and the amorphous modification of selenium being 22-1 Cals.1 Water causes a gradual decomposition of the chloride, selenium dioxide and selenium being formed 2... 

Crystalline Tellurium. — Molten tellurium solidifies to a brittle, silvery, crystalline mass, which is easily powdered. The crystalline modification can also be obtained by sublimation of the element or by its slow formation, for example in the gradual decomposition of hydrogen telluride5 or in the slow atmospheric oxidation of an aqueous solution of an alkali telluride.6 When obtained of appreciable size the crystals are generally found to be prismatic, of the trigonal system, and isomorphous with metallic selenium (a c=l 1-3298 a=86-8°).7... 

Part of the nitroglycerine dissolved in this mixture of acids undergoes hydrolysis. Concentrated hydrochloric acid does not dissolve nitroglycerine. On heating, a gradual decomposition occurs accompanied by a dark yellow colour due to hydrolysis and the production of nitrosyl chloride. 

Chemical Properties.—Arsine in the pure state is fairly stable, but in accordance with its endothermic nature it undergoes gradual decomposition into arsenic and hydrogen even when kept in a sealed tube in the dark. Under the latter conditions black particles of arsenic... 

DECOMPOSITION (Chemical). A chemical change tn which a single chemical substance is broken up into two or more other substances, which differ from each other and from the parent substance in chemical identity. Complete decomposition refers to such a condition of the products that they are not readily decomposed further, c.g.. such decomposition products as ammonia and carbon dioxide. Degnidtniim refers to gradual decomposition in which the molecule is diminished in size in small steps. See also Degradation (Chemical). 

E. Divers and T. Haga noted the gradual decomposition of the salt when it is impure. The salt readily dissolves in water and there is a marked fall of temp.. 

Acetone dicarboxylic acid was first obtained by the action of concentrated sulfuric acid upon citric acid.1 It has been made also by the gradual decomposition of a mixture of lime and sucrose.2 The most satisfactory method, however, for producing this substance, is by the action of fuming sulfuric acid upon citric acid. Details of this preparation have been modified a number of times with the intention of improving the yield.3... 

Routine H and 13C NMR characterization of 1,2,4-trioxolanes and 1,2,4-trithiolanes has been performed. In the case of fluorine substituted ozonides, Teflon NMR tubes had to be employed as glass catalyzes gradual decomposition at room temperature and above. 

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