Solubility and decomposition

Holdren, M.W., Spicer, C.W., and Hales, J.M. Peroxyacetyl nitrate solubility and decomposition rate in acidic water, Atmos. Environ., 18(6) 1171-1173, 1984. 

Park, J.-Y. and Lee, Y.-N. Solubility and decomposition kinetics of nitrous acid in aqueous solution, J. Phys. Chem., 92(22) 6294-6302, 1988. 

Holdren, M. W., C. W. Spicer, and J. M. Hales, Peroxyacetyl Nitrate Solubility and Decomposition Rate in Acidic Water, Atmos. Environ., 18, 1171-1173 (1984). 

Ru(tpy)2] + units are present in the branches of dendrimers 24 and 25, which have identical molecular formula and are the first example of dendritic constitutional isomers [105]. These isomers feature similar solubility and decomposition temperature, whereas the electrochemical behavior (in acetonitrile), due to the four... 

Solutions of the alkali elements, in a range of polar solvents, have been shown to contain M , M ", e, and the unusual anion, M , in equilibrium. Early studies were hindered by solubility and decomposition problems. The addition of a macrocylic chelate to these solutions provided a means of increasing the solubility of the metal as well as controlling what species predominate in solution. A metal chelate mole ratio of 2 1 leads to formation of the alkalides [M -i- L] M while a ratio of 1 1 leads to the electrides (see 10.2.2.5), [M -t- L] e (where M and M = Li, Na, K, Rb, Cs (not always the same) and L = two crown ethers (combinations of 12-C-4, 15-C-5, 18-C-6) or one cryptand [2.2.2]). Furthermore, these unique compounds could be isolated as solids and fully characterized. A wider range of alkalides than electrides is known including those with other chelates such as ethylenediamne , and aza crown ethers . Some representative examples are [Na -t- crypt]Na"(the first to be structurally characterized) , and [Cs + 18-C-6)(15-C-5)]Na- . 

A careful and detailed study of the solubility and decomposition kinetics of nitrous acid in aqueous solution has appeared. This is part of an excellent program of work on atmospheric chemistry, and provides valuable quantitative data, particularly in terms of solubility parameters. Stanbury et have bubbled N0 2 in a stream of N2 into alkaline aqueous solutions of Na N02, and determined the amount of. This is a difficult experiment to do well, and has produced... 

Peroxides have many uses in polymer manufacture. They are used as initiators in radical polymerization processes such as the formation of PVC, polystyrene, and low density polyethylene. They can also be added in a polymer formulation for various reasons. Sometimes this is to crosslink an unsaturated polymer such as unsaturated polyesters used in fiberglass formulations. Other times it is to graft one polymer to another chemical or polymer by a radical reaction. The choice of the peroxide is dictated by considerations such as storage stability, solubility, and decomposition to form radicals at a temperature near the desired reaction. Common peroxides include benzoyl peroxide, di-t-butylperoxide, and dicumylperoxide (DICUP). 

While a number of interesting reactivity patterns have been observed, these systems suffer from poor solubility and decomposition via abstraction of cyclopentadienyl ring hydrogen atoms. Permethylation of the ligand (79) circumvents a number of these problems, and for X = Si(CH3)2 a new series of coordinatively unsaturated, thermally stable, and highly reactive actinide hydro-carbyls can be prepared [71, 72] ... 

Such a delocalized active complex might be expected to be more stable and give a diene polymer having a high molecular weight. But the range of solvents in which stable sodium-metal alkoxide complex solutions could be obtained was severely limited by solubility and decomposition problems, especially in hydrocarbon media. The application of dicyclohexyl-18-crown-6 or DCHE (ll) to complex the sodium metal as reported by Schire has... 

Ucon HTF-500. Union Carbide Corp. manufactures Ucon HTE-500, a polyalkylene glycol suitable for Hquid-phase heat transfer. The fluid exhibits good thermal stabHity in the recommended temperature range and is inhibited against oxidation. The products of decomposition are soluble and viscosity increases as decomposition proceeds. The vapor pressure of the fluid is negligible and it is not feasible to recover the used fluid by distiHation. Also, because the degradation products are soluble in the fluid, it is not possible to remove them by filtration any spent fluid usuaHy must be burned as fuel or discarded. The fluid is soluble in water. 

Several commercial grades are available fine crystals of 99 to 100% purity, large crystals, pressed lumps, rods, and granular material. Double-Decomposition Methods. Double-decomposition processes all iavolve the reaction of sodium chloride, the cheapest chlorine source, with an ammonium salt. The latter may be suppHed directiy, or generated in situ by the reaction of ammonia and a supplementary iagredient. Ammonium chloride and a sodium salt are formed. The sodium salt is typically less soluble and is separated at higher temperatures ammonium chloride is recovered from the filtrate by cooling. 

Bina Selenides. Most biaary selenides are formed by beating selenium ia the presence of the element, reduction of selenites or selenates with carbon or hydrogen, and double decomposition of heavy-metal salts ia aqueous solution or suspension with a soluble selenide salt, eg, Na2Se or (NH 2S [66455-76-3]. Atmospheric oxygen oxidizes the selenides more rapidly than the corresponding sulfides and more slowly than the teUurides. Selenides of the alkah, alkaline-earth metals, and lanthanum elements are water soluble and readily hydrolyzed. Heavy-metal selenides are iasoluble ia water. Polyselenides form when selenium reacts with alkah metals dissolved ia hquid ammonia. Metal (M) hydrogen selenides of the M HSe type are known. Some heavy-metal selenides show important and useful electric, photoelectric, photo-optical, and semiconductor properties. Ferroselenium and nickel selenide are made by sintering a mixture of selenium and metal powder. 

Physical Properties. Thiophosgene [463-71-8] (thiocarbonyl chloride), CSCI2, is a malodorous, red-yeUow Hquid (bp 73.5°C, ( 20 1.5442). It is only slightly soluble with decomposition in water, but it is soluble in ether and various organic solvents. 

Traditionally, sodium dichromate dihydrate is mixed with 66° Bh (specific gravity = 1.84) sulfuric acid in a heavy-walled cast-iron or steel reactor. The mixture is heated externally, and the reactor is provided with a sweep agitator. Water is driven off and the hydrous bisulfate melts at about 160°C. As the temperature is slowly increased, the molten bisulfate provides an excellent heat-transfer medium for melting the chromic acid at 197°C without appreciable decomposition. As soon as the chromic acid melts, the agitator is stopped and the mixture separates into a heavy layer of molten chromic acid and a light layer of molten bisulfate. The chromic acid is tapped and flaked on water cooled roUs to produce the customary commercial form. The bisulfate contains dissolved CrO and soluble and insoluble chromic sulfates. Environmental considerations dictate purification and return of the bisulfate to the treating operation. 

Agronomic Properties and Nutrient Release Mechanism. The conversion of UF reaction products to plant available nitrogen is a multistep process, involving dissolution and decomposition. Materials are slow to enter the soil solution by virtue of their low solubiUty. Longer polymer chain products are less soluble than shorter chains and take longer to become available to the plants. 

Another way of applying the selective extraction method directly on the initial solution is to produce a solution of low acidity. This can be achieved by using the hydrofluoride method for fluorination and decomposition of raw material. As was discussed in Paragraph 8.2.2, the raw material is fluorinated by molten ammonium hydrofluoride yielding soluble complex fluorides of ammonium and tantalum or niobium. The cake obtained following fluorination is dissolved in water, leading to a solution of low initial acidity that is related for the most part to the partial hydrolysis of complex fluoride compounds. The acidity of the solution is first adjusted to ensure selective tantalum extraction. In the second step, the acidity of the raffinate is increased to provide the necessary conditions for niobium extraction. 

It is instructive to consider what steps may be taken to ascertain qualitatively the structural type and physical state of a given polymeric substance. To this end one should first of all determine whether or not the substance is soluble without decomposition in any solvent,... 

While extensive CO ligand loss can be induced in the gas phase in aqueous solution, 1 - 3 are moderately soluble and stable for days. No signs of hydrolysis or decomposition were observed by 31P NMR spectroscopy. The logPo/w values of 1 - 3 were determined (see Table 1). 

In water, tetraalkyl lead compounds are subject to photolysis and volatilization with the more volatile compounds being lost by evaporation. Degradation proceeds from trialkyl lead to dialkyl lead to inorganic lead. Tetraethyl lead is susceptible to photolytic decomposition in water. Triethyl and trimethyl lead are more water-soluble and therefore more persistent in the aquatic environment than tetraethyl or tetramethyl lead. The degradation of trialkyl lead compounds yields small amounts of dialkyl lead compounds. Removal of tetraalkyl lead compounds from seawater occurs at rates that provide half-lives measurable in days (DeJonghe and Adams 1986). 

Soil solution is the aqueous phase of soil. It is in the pore space of soils and includes soil water and soluble constituents, such as dissolved inorganic ions and dissolved organic solutes. Soil solution accommodates and nourishes many surface and solution reactions and soil processes, such as soil formation and decomposition of organic matter. Soil solution provides the source and a channel for movement and transport of nutrients and trace elements and regulates their bioavailability in soils to plants. Trace element uptake by organisms and transport in natural systems typically occurs through the solution phase (Traina and Laperche, 1999). 

B,j3,B"-Trichloroborazine forms white crystalline needles, m.p. 83.9 to 84.5°. It is extremely sensitive to moisture and decomposes violently in water. It is soluble without decomposition in anhydrous nonprotonic organic solvents such as benzene, ethyl ether, and carbon tetrachloride. 

As it was not known what kind of organic matter acts as the major ligand for chromium in seawater, Nakayama et al. [38] used ethylene diaminetetra-acetic acid (EDTA) and 8-quinolinol-4-sulfuric acid to examine the collection and decomposition of organic chromium species, because these ligands form quite stable water-soluble complexes with chromium (III), although they are not actually present in seawater. Both of these chromium (III) chelates are stable in seawater at pH 8.1 and are hardly collected with either of the hydrated oxides. The organic chromium species were then decomposed to inorganic... 

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