Inorganics, solubility concentrated solutions

Mercuric Sulfide. Mercuric s A ide[1344 8-5] HgS, exists ia two stable forms. The black cubic tetrahedral form is obtaiaed when soluble mercuric salts and sulfides are mixed the red hexagonal form is found ia nature as cinnabar (vermilion pigment). Both forms are very insoluble in water (see Pigments, inorganic). Red mercuric sulfide is made by heating the black sulfide in a concentrated solution of alkah polysulfide. The exact shade of the pigment varies with concentration, temperature, and time of reaction. 

Chemical Properties and Reactivity. LLDPE is a saturated branched hydrocarbon. The most reactive parts of LLDPE molecules are the tertiary CH bonds in branches and the double bonds at chain ends. Although LLDPE is nonreactive with both inorganic and organic acids, it can form sulfo-compounds in concentrated solutions of H2SO4 (>70%) at elevated temperatures and can also be nitrated with concentrated HNO. LLDPE is also stable in alkaline and salt solutions. At room temperature, LLDPE resins are not soluble in any known solvent (except for those fractions with the highest branching contents) at temperatures above 80—100°C, however, the resins can be dissolved in various aromatic, aUphatic, and halogenated hydrocarbons such as xylenes, tetralin, decalin, and chlorobenzenes. 

Although buffer components are often present at the highest concentration in a medium, metals can also bind to inorganic ligands in solution. Ligands such as CL, OHand SO can form soluble complexes with many metals.127 These complexes remain in solution, but are considered to be less bioavailable than the free, ionic species under most conditions.97 Even though other soluble metal species are considered less bioavailable, they may play roles in metal toxicity. 

Chitosan features far more than chitin in research into applications. This is largely due to their difference in solubility characteristics, chitosan being more amenable to practical manipulation. Chitin is in fact rather more intractable than cellulose, since it is insoluble in those solvents, such as cuprammonium hydroxide, that are commonly used to dissolve cellulose. Chitin is soluble in hot concentrated solutions of certain inorganic salts capable of... 

This simplified calculation is used to illustrate basic computational techniques. It assumes that all of the Fe(OH)3(aq) is a true solute. The quality of this assumption is a matter of debate as at pH 8, Fe(OH)3(aq), tends to form colloids. Thus, laboratory measurements of ferrihydrite solubility yield results highly dependent on the method by which [Fe(lll)]jQ(gj is isolated. Ultrafiltration techniques that exclude colloids from the [Fe(lll)]jQjgj pool produce very low equilibrium solubility concentrations, on the order of 0.01 nM. This is an important issue because a significant fraction of the iron in seawater is likely colloidal, some of which is inorganic and some organic. In oxic... 

The solubility of many inorganics in aqueous solution is available in the book by Linke and Seidell (1958). This reference also contains the solubilities of electrolytes in the presence of other species. As an example. Figure 1.7 shows the solubility of NaCl as a function of NaOH concentration. As a general rule, the solubility of most inorganics in water is available as a function of temperature. What is more difficult to find is the effect of other species on the solubility. If several other sf)ecies are present the... 

Very recently, Schmidt et al. synthesized novel polyamides 51 by using arylsubstituted terephthalic acids moieties such as para- or ortfto-terphenyI-2,5-dicarboxylic acids in combination with substituted and non-coplanar diamines [70]. Those polyamides 51 from substituted diacids, diamines or non-coplanar diamines showed high solubility in DMAc, and in most cases without addition of inorganic salts (LiCl). In DMAc (LiCl), polyamide 51ca (rjinh = 1-63 dl/g) forms a lyotropic liquid crystalline phase at > 8 wt % at room temperature, and at > 5 wt % at 110 °C for polyamide 51ae (T)i h = 3.58 dl/g). On the other hand, with the copolyamides 52 the critical concentrations of liquid crystal formation are around 40-45% at room temperature. For these copolyamides, concentrated solutions in DMAc/LiCl with polymer concentration up to 50wt% could be prepared for polymers with x > 0.6. 

To ensure that reaction occurs in homogeneous solution, solvents are chosen that dissolve both the alkyl halide and the ionic salt. Alkyl halides are soluble in organic solvents, but the salts often are not. Inorganic salts are soluble in water, but alkyl halides are not. Mixed solvents such as ethanol-water mixtures that can dissolve enough of both the substrate and the nucleophile to give fairly concentrated solutions are frequently used. 

Spinning of PPTA. Unlike MPDI, high molecular weight PPTA is not soluble in amide solvents, with or without the addition of inorganic salts. Formation of fibers from PPTA became possible when it was discovered that concentrated solutions of the polymer in 100% sulfuric acid had relatively low viscosity, could be spun at moderate temperatures, and that the PPTA did not degrade rapidly at those conditions (36). This discovery was the result of the study of nematic solutions of PBA and PPTA (22,36) and substantiated the theoretical predictions of Flory (39). A schematic of such a process is shown in Figure 6. 

The presence of salt alone in an aqueous solution is known to increase surface tension. However, a net decrease in surface tension with respect to that of water is commonly observed in mixed inorganic/organic aqueous solutions containing surfactants. In mixed inorganic/organic solutions, especially at high ionic concentrations, the solubility of the organic component may decrease, in a... 

Mixture of Glu and Asp is eluted from the coliunn 2 by an acidic solution (conventionally HCl) and sent to the forth column containing OH form of a strong anion exchanger. This step exploits the phenomenon of ion exchange isothermal supersaturation. The colmnn concentrates these two amino acids simultaneously separating them from impmities of inorganic anions. The concentrated solution at the colmnn output contains a mixture of both amino acids. However, concentration of glutamic acid two-three folds exceeds its solubility this product precipitates as pme crystals. 

The high sodium ion concentration results in facile crystallisation of the sodium salt. This process of salting out with common salt may be used for recrystallisation, but sodium benzenesulphonate (and salts of other acids of comparable molecular weight) is so very soluble in water that the solution must be almost saturated with sodium chloride and consequently the product is likely to be contaminated with it. In such a case a pure product may be obtained by crystallisation from, or Soxhlet extraction with, absolute alcohol the sul-phonate is slightly soluble but the inorganic salts are almost insoluble. Very small amounts of sulphones are formed as by-products, but since these are insoluble in water, they separate when the reaction mixture is poured into water ... 

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