Solubility of solvents

The meaning of the surface excess is illustrated in Fig. 1, in which the solid line represents the actual concentration profile of an adsorbate i, when the bulk concentration of i in the phase a (a = O or W) is c . The hatched area corresponds to be the surface excess of i, T,. This quantity depends on the location of the dividing surface. On the other hand, the experimentally accessible quantity should not depend on the location of the artificially introduced dividing surface. The relative surface excess, which is independent of the location of the dividing surface, is defined by relativizing it with respect to those of certain reference components. In oil water interfaces, the mutual solubility of solvents can be significant. The relative surface excess in Eq. (3) is then related to the surface excesses through... 

Table 1.4 Solvent descriptors of organic solvents commonly used for biocatalysis. Sw/o (solubility of water in solvent, wt%) So/w (solubility of solvent in water, wt%) and e (dielectric constant) values from [78], log P (P = partition coefficient between octanol and water), ET (empirical polarity parameter by Reichardt-Dimroth) and HS (Hildebrand solubility parameter, )l, cm J, ) from [79].

T. Michalowski, Effect of Mutual Solubility of Solvents in Multiple Liquid-Liquid Extraction, /. Chem. Ed. 2002, 79, 1267. 

The fragment additive 7t values can therefore serve to estimate the solubility of solvents (and solutes in general) in water, with a standard error of - 30%, see Figure 4.6. 

The correlation between the molar aqueous solubility of solvents log(s/mol dm"3), and the 1 -octanol/water distribution ratio, log P... 

In general, the solubility of solvent-free complexes is very low. However, coordination of Zr with donor solvents gives more soluble compounds. Depending on the extent of the steric effect of the pentahapto ligand, solvent mono or bis adducts are obtained. However stronger electron-donating molecules such as phosphanes do not form adducts, according to the Tewis acidity of the metal. 

Low solubility of solvent into the silicon During epitaxial process, atoms of the solvent are incorporated in the Si crystal. Their incorporation can modify the electronic properties of the layer. Actually, many metallic impurities act as recombination centre or as dopant and reduce the lifetime of minority carriers. Solvent purity is also an important parameter to avoid other impurities. 

Aqueous solubility of solvents is related to polarity and dipole moment. Many solvents are hygroscopic and need drying agents, such as molecular sieves to remove moisture from them. Solubility of solvents in water and vice versa are listed in Table 6. It is observed that the solvents with -OH, -C(0)Me, -COOH, -NH2, and -CN groups have high degree of miscibility with water, whereas hydrocarbons, esters, and chlorinated compounds have a low solubility in water. 

The decrease in Aj is attributed to two factors (1) poor solubility of solvent, since THF is not a good solvent for ionic groups (2) attraction between ion pairs in low dielectric constant medium. If the former is the only cause, we should obtain the same molecular weight irrespective of the ion content. However, as is shown in Figure 7, the molecular weight increases with ion content. Therefore, the decrease in definitely reflects the attractions between ion pairs in THF. The second virial coefficient of ionomer solutions is composed of two parts f32.331 i.e., — Ai +... 

We now make an important simplifying assumption we assume that the solid phase consists only of component 2 that is, there is no solubility of solvent in the solid phase. (This is usually a good assumption whenever components 1 and 2 have different molecular structures because miscibility in the solid phase is highly sensitive to small details in molecular geometry.) In that event we need consider only Eq- (1.6-2) which we rewrite... 

In the simplest case, tba solid phase is pure 2 (no solubility of solvent in the solid), Eq- (1.6-11) does not apply, and in Eq. (1 -6-12) we may set/f equal to/i. the fogacity of pure solid 2. The (single) equation for gas-solid equilibrium is then... 

Knowledge of the solubility of solvents in water is useful in predicting their behaviour in several fields. Highly water-soluble solvents carry materials and migrate themselves into the biosphere. 

TABLE II Solubility of Solvents in Thiokol Liquid Polymers"... 

Figure 12.1.27. Separation factor vs. solubility of solvents in water. [Adapted, by permission, from M Hoshi, M Kobayashi, T Saitoh, A Higuchi,...

Figure 12.1.27 shows the relationship between the separation factor and the solubility of solvents in water. The separation of solvent by a pervaporation membrane occurs less efficiently as solvent solubility increases.The more concentrated the solution of solvent, the faster is the separation (Figure 12.1.28). Separation of hexane from a mixture with heptane is similar (Figure 12.1.29). The acrylic membrane shows good selectivity. These examples demonstrate the usefulness of pervaporation membranes in solvent recovery proeesses.

The lipid solubility of solvents also favors their deposition of into lipid rich organ systems such as the liver. The toxicity of a particular solvent may be enhanced by its long residence time in the liver. ... 

In the case of the following systems, predict the distribution of substance C and selectivity of B using the data indicated, neglecting the effect of solubility of solvents A and B. Compare with the observed data. 

The solvent which has been almost completely denuded of solute may be suitable for recycling directly back to the first extractor, for re-extraction of more solute. Alternatively, it may require treatment before re-use, e.g. an alkaline wash to remove impurities which have accumulated during its previous contact with acid aqueous phases. It is advisable for any treatment process to be continuous, as are the extraction and backwash processes, to preserve the continuity of operations. The cost of solvent can be an important item of process economics unless it is efficiently recovered. Systems are therefore chosen with low solubilities of solvent in the aqueous phases, and care should be taken to avoid entrainment of solvent, general spillages, etc. 

Solvent Solubility of Water, wt% in Solvent Ratio of Molecular Weights to Water Reaction Equivalent Concentration of Solvent, wt% Solubility of Solvent, wt% in Water... 

Related to the mutual solubility of solvents with water is their lipophilicity or hydrophobicity that can be described by (the logarithm of) their partition coefficient between n-octanol and water, log. The more hydrophobic a substance is, the larger... 

TABLE 3.11 Mole Fraction Solubilities of Solvents in Water, Xj, and of Water in Solvents, and the Logarithm of the Octanol/Water Partition Coefficients of the Solvents, log, at 25°C... 

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