Intermolecular force solutions and

SOL.24.1. Prigogine, Forces intermoleculaires et volume d exces des solutions (Intermolecular forces and excess volume in solutions), Bull. Soc. Chim. Beiges 62, 125-137 (1953). 

Types of Solutions Intermolecular Forces and Solubility IntermoleciJar Forces h Solution Liquid Solutions... 

Stillinger F 1973 Structure in aqueous solutions from the standpoint of scaled particle theory J. Solution Chem. 2 141 Widom B 1967 Intermolecular forces and the nature of the liquid state Sc/e/ ce 375 157 Longuet-Higgins H C and Widom B 1964 A rigid sphere model for the melting of argon Mol. Phys. 8 549... 

The difference between the log P of a given compound in its neutral form (log P ) and its fully ionized form (log P ) has been termed dialog P ) and contains series-specific information, and expresses the influence of ionization on the intermolecular forces and intramolecular interactions of a solute [44, 51, 52]. 

To have an ideal solution, the solvent-solvent, solute-solute and solvent-solute intermolecular forces should be as nearly identical as possible. Solution (c) consisting of CH4( ) dissolved in CH3CH3( ) would be the most ideal. 

Notable in the tricolorin A (106) solid state is the presence of 18 water molecules in the unit cell, and an anisotropic repartitioning of the hydrophobic and hydrophilic sections. The water molecules form a dense network that creates a dividing layer between the hydrophilic faces (see Fig. 6). The high water content indicates that the conformation in the solid state is not dominated by intermolecular forces and could be indicative of a similar conformation in both solution and supermolecular... 

The dissolution of a solute in a solvent has associated with it a free-energy change, AG = AH — TAS. The enthalpy change is the heat of solution (AHsoin), and the entropy change is the entropy of solution (ASsoin). Heats of solution can be either positive or negative, depending on the relative strengths of solvent-solvent, solute-solute, and solvent-solute intermolecular forces. Entropies of solution are usually positive because disorder increases when a pure solute dissolves in a pure solvent. 

We have covered a great deal of territory. We discussed the nature of chemistry, the structure of atoms and chemical compounds, and the properties of elements as reflected in the periodic table. We explored fundamental classes of chemical reactions such as redox reactions, acid-base reactions, and displacement reactions. We laid out the theory that describes the nature of the chemical bond and the principles of chemical reactions. We discussed the practical considerations of intermolecular forces and concentration and considered the rarefied properties and reactions of gases. We contrasted the slippery properties of solutions with the concrete properties of solids. We delved into thermo-... 

We employ y to denote the activity coefficient defined relative to the pure substance and y the activity coefficient defined relative to an infinitely dilute solution. The only other use of a superscript asterisk (except in the statistical mechanical discussion of intermolecular forces and liquids) is to distinguish the pressure p from the fugacity, p. ... 

Systems Containing More Than Two Components. As in binary systems, the behavior of systems containing more than two components can be understood on the basis of intermolecular forces and solubility parameters. Water and tetrachloromethane have widely differing solubility and hydrogen bond parameters, and are therefore immiscible. Added acetone dissolves partly in the aqueous phase due to hydrogen bond formation, and partly in the tetrachloromethane phase due to dispersion and induction forces. Twice as much acetone dissolves in the aqueous phase as in tetrachloromethane. On increasing the acetone concentration a homogeneous solution is obtained. The added solvent thus acts as a solubilizer for the two immiscible solvents. 

The most signifiamt properties are intermolecular forces and temperature. If there are favorable interactions between the solute and the solvent, solubility will be higher. This is actually a balemce of the interactions of the solute with the solvent and the stability of the solute in the solid phase. Temperature edso influences solubility, and for most substances, solubility increases as the temperature of the solvent rises. 

In an ideal solution intermolecular forces are the same between all molecules, regardless of species differences in those forces produce nonzero values for excess properties. In particular, magnitudes and signs of excess properties are determined by imbalances in the strengths of interactions between molecules of the same component (like interactions) as compared to those between molecules of different components (unlike interactions). Figure 5.1 illustrates these points by showing at 25°C for... 

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