Solubility prediction reference solvents

It is difficult to describe all possible fields of application of analytical isotachophoresis. To predict feasablllty for Isotachophoresis as an analytical method, the ratio of molecular weight to effective charge can be used. Generally this ratio should not exceed 3000. Needless to say the compound must have a sufficient solubility in the solvent chosen. A brief survey of applications will be given and further information can be found in the references [3,5,6]. ... 

Therefore, if the binary constant, A 2r is set or determined from experiment. Equation 9.33 determines k23- Second, this also means that one can predict solute solubility in a solvent i from that in a convenient reference solvent, R,... 

In the following paragraphs, some application examples will be presented, starting with a short introduction to COSMO-RS (Section 9.2), followed by solubility predictions in pure and mixed solvents (Section 9.3). A modification using several reference solubilities is shown in Section 9.4 whereas Section 9.5 is about quantitative structure-property relationship (QSPR) models of the melting point and the enthalpy of fusion. The final Sections 9.6 and 9.7 deal with COSMO-RS-based coformer selection for cocrystal screening and the related issue of solvent selection to avoid solvate formation. 

At a somewhat reduced accuracy it is also possible to circumvent the sometimes costly quantum chemical calculations and to generate o-profiles on-the-fly from fragments of precomputed COSMO files stored in a database. This approach is implemented in the software COSMOquick and is particularly useful for solubility prediction using one or several reference solvents (see also Section 9.4). 

SOLUBILITY PREDICTION WITH MULTIPLE REFERENCE SOLVENTS... 

An emulsifier system must cause the concentrate to disperse spontaneously into small, stable droplets when mixed with water. To accomplish this, the surfactant system must have a most favorable solubility relationship a proper balance between oil and water solubility or, in other words, a favorable hydrophile-lipophile balance in solubility. This balance in solubility is frequently referred to as HLB and was first described by Griffin (6). However, the HLB system is based on the structure of a surfactant molecule and, therefore, predicts the behavior of a single molecule. It does not take into account tr 3 fact that many surfactants form micelles in organic solutions. If a micelle is formed, its HLB may have no relationship to the HLB of the monomer unit. Therefore, to select an emulsifier well, we will need a better understanding of the behavior of surfactants in organic solvents. 

One of the three types of metathesis reactions is driven by the production of an insoluble solid. While we are going to go much more in depth about solubility in Chapter 15, there are some basic rules you can learn now that will provide you with more than enough information to predict the products of chemical reactions. These basic rules, usually referred to as solubility rules, are listed in Table 11.5. When reading the chart, keep in mind that all the solutions listed are aqueous solutions (water is the solvent). The term insoluble is not exactly correct. 

The square root of the cohesive pressure c as defined in Eq. (3-5) has been termed the solubility parameter 8 by Hildebrand and Scott [98] because of its value in correlating and predicting the solvency of solvents for non-electrolyte solutes [cf. Eqs. (2-1) and (5-77) in Sections 2.1 and 5.4.2, respectively]. Solvency is defined as the ability of solvents to dissolve a compound [118]. A selection of 8 values is given in Table 3-3 see also references [99, 177]. 

Solute Mixed solvent Reference Deviation (%) between experimental and predicted (Eq. (9)) solubilities ... 

A recently developed model for the S-L-V equilibrium (63) utilizes the PMVF of the solvent in a binary mixture and the solute solubility at a reference pressure. This approach uses Eq. (50) to predict the ternary liquid mole fractions for the S-L equilibrium at different CO2 mole fractions corresponding to different pressures and at a fixed temperature. Next the pressure is adjusted to satisfy the isofugacity criterion for the L-V equilibrium, to permit the prediction of the vapor phase composition at which all three (S-L-V) phases coexist. This is repeated for other temperatures to obtain the P-T trace of the S-L-V equilibrium. The P-T trace for the constant liquid phase composition of the... 

How can we predict whether a precipitate will form when a compound is added to a solntion or when two solutions are mixed It depends on the solubility of the solute, which is defined as the maximum amount of solute that will dissolve in a given quantity of solvent at a specific temperature. Chemists refer to substances as soluble, slightly soluble, or insoluble in a qualitative sense. A substance is said to be soluble if a fair amount of it visibly dissolves when added to water. If not, the substance is described as slightly soluble or insoluble. All ionic compounds are strong electrolytes, but they are not equally soluble. 

Many attempts were made to explain lipophilicity by related properties, e.g. by solubility, solvent-accessible surface, and charge distributions calculated from semiempirical methods ([190, 272 — 284] and references cited therein) while some of the results allow a better understanding of the intrinsic nature of lipophilicity, none of these alternative approaches have led to a reliable log P prediction system so far. 

An ideal solution is one in which the interaction between solute and solvent molecules is identical with that between the solute molecules and the solvent molecules themselves. From this definition alone it is clear that a truly ideal solution is most unlikely to exist, but the concept is still very useful as a reference condition. For instance, if the solute and solvent did form an ideal solution, the solubility could be predicted from the van t Hoff equation ... 

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