Group additivity for partial molal heat capacities and volumes of alkanes in methanol at 25�C

Heat capacities and volumes of some non-electrolytes in N,N-dimethylformamide at 298.15 K

“…The values of ACin, and 6CT,2 for several solutes in DMF are also presented in Table 4. These values show that ACin, in D M F solution is negative for all non-electrolytes investigated, just as it was found for methanolic solutions (water was an exception), and for aqueous solutions of substances that were capable of interacting strongly with water (methanol, NMA, acetone, DMSO, water) (24). The positive ACin, values, characteristic of aqueous solutions of hydrophobic substances were not found in DMF solution.…”

Apparent molar volumes of aqueous solutions of some organic solutes at the pressure 28 MPa and temperatures to 598 K

“…(36,37) French and Criss (38) pointed out that the covolume can be considered to be the volume of a noninteracting point mass k T RT where k T is the isothermal compressibility of the pure solvent. This effect of a point mass on the volume is also called the standard state term, and is a well-established effect.…”

“…for aqueous (36,37) and nonaqueous (38) solutions, where V c is the ''covolume'', n j is the number of groups j in the compound, and V j is the volume of group j. Corrections for various steric factors can be added to equation (10) when enough information is available. (36,37) French and Criss (38) pointed out that the covolume can be considered to be the volume of a noninteracting point mass k T RT where k T is the isothermal compressibility of the pure solvent.…”

Partial molar volumes of organic solutes in water. XXI: Cyclic ethers at temperatures T= (278 to 373) K and at low pressure

“…With cyclic molecules investigated here the co-volume term naturally appears when the additivity scheme is applied to experimental data contrary to the non-cyclic molecules where the co-volume term should be introduced into the group additivity scheme by imposing additional conditions (e.g., [27,29] noted below) to get the resulting magnitudes of the group contributions realistic with respect to group volumes derived from volumes of constituent atoms (it concerns particularly to groups of the hydrocarbon frame as -CH 3 , -CH 2 -, >CH-, >C<). From the molecular point of view the co-volume term represents the partial molar volume of a non-interacting point mass (a solute with no groups) and its ''hard-core" part can be interpreted as the volume inaccessible by the centres of the solvent molecules surrounding the point molecule of the solute [28].…”

“…From the molecular point of view the co-volume term represents the partial molar volume of a non-interacting point mass (a solute with no groups) and its ''hard-core" part can be interpreted as the volume inaccessible by the centres of the solvent molecules surrounding the point molecule of the solute [28]. Thus the co-volume term should be the same for all solutes in a particular solvent and determined by the properties of the solvent [29]. Sometimes it is called standard state term since it includes all information concerning standard state and thus allows the group contributions to be independent of a selection of standard state.…”