Pressure-Volume-Temperature Relations in Solutions. V. The Energy-Volume Coefficients of Carbon Tetrachloride, Water and Ethylene Glycol

N o~i o NISH~MURA, TOHRU TANAKA, and TAKUSH~ MOTOYAMA. Can. J. Chem. 65, 2248Chem. 65, (1987. A critical test of additivity for partial molar volume has been made at 25' C in CCI4 with polyethylene glycol dimethyl ethers, crown ethers, cycloalkanes, n-alkanes, and others. Plots of partial molar volume at infinite dilution (v O ) against the properly chosen number of repeating unit ( n ) are linear except for small cyclic molecules, and the slopes of homologous straight chain and ring compounds are the same. The values of v O extrapolated to 11 = 0 for cycloalkanes and crown ethers support the validity of the contribution due to the translational kinetic energy that has been predicted recently on a theoretical basis. The importance of packing efficiencies around the solute molecules has been examined by means of simple models.NORIO NISHIMURA, TOHRU TANAKA et TAKUSH~ MOTOYAMA. Can. J. Chem. 65,2248Chem. 65, (1987. OpCrant i 25"C, dans des solutions de CC14, on a effectuC une Cvaluation critique de I'additivitC des volumes molaires partiels pour des Cthers dimtthyliques du polyCthylkne glycol, des Cthers couronnes, des cycloalcanes, des n-alcanes et d'autres composCs. A l'exception des molCcules contenant des petits cycles, on a trouvC qu'il existe une relation linCaire entre les volumes molaires partiels i dilution infinie (a O) et le nombre choisi appropriC d'unitts periodiques (n); de plus, les pentes des courbes pour les composCs homologues aliphatiques sont les mkmes que celles pour les composts cycliques. Pour les cycloalcanes et pour les Cthers couronnes, les valeurs de (v O ) extrapolCes i n = 0 sont en accord avec la prCdiction qui a rCcemment CtC faite sur une base thCorique et selon laquelle on pr6voit une contribution de la part de 1'Cnergie cinCtique de translation. Utilisant des moddes simples, on a CtudiC I'importance des efficacitCs d'empilement autour des moltcules de solutCs.[Traduit par la revue]

Section: For Cycloalkanes We Havementioning

confidence: 90%

Section: For Cycloalkanes We Havementioning

confidence: 99%

See 1 more Smart Citation

Additivity of the partial molar volumes of organic compounds

Nishimura¹,

Tanaka²,

Motoyama³

1987

“…In terms of classical mechanics the total energy of a fluid, U, may be regarded as the sum of three terms (3,(11)(12)(13).…”

Section: Energy-volume Coefjicientsmentioning

confidence: 99%

The Thermal Pressure and Energy–Volume Coefficients of the Methyl Alcohol – Water and t-Butyl Alcohol – Water Systems

Macdonald¹,

Hyne²

1971

Thermal pressure and energy-volume coefficients have been determined for various methyl alcoholwater and t-butyl alcohol -water mixtures at several temperatures in the range 19-55 "C. The energy-volume coefficient is found to pass through a maximum at 0.3-0.4 mole fraction methyl alcohol andO.l mole fraction t-butyl alcohol. This behavior is consistent with the average intermolecular distance passing through a minimum in both systems at the corresponding solvent compositions. The relationship between the energy-volume coefficient, the cohesive energy density, and the structure of aqueous binary systems is examined. The temperature dependence of the thermal pressure coefficient is discussed in terms of the effect of temperature on the susceptibility of the entropy of the two systems to isothermal expansion.Le coefficient thermique de la pression et le coefficient d'knergie-volume ont Ct C determines pour divers melanges d'alcool methylique-eau et alcool I-butylique-eau a plusieurs temperatures entre 19 et 55 "C. Le coefficient tnergie-volume passe par un maximum pour une fraction molaire d'alcool methylique comprise entre 0.3 et 0.4 et pour une fraction molaire d'alcool t-butylique de 0.1. Ce comportement concorde avec 1e fait que la distance intermol6culaire moyenne passe par un minimum pour les deux systemes aux compositions correspondantes en solvant. La relation entre le coefficient d'energievolume, la densite d'energie de cohesion et la structure des systemes aqueux binaires est examinee. La variation du coefficient thermique de la pression avec la temperature est analysee en termes d'effet de temperature sur la sensibilite de l'entropie des deux systemes a I'expansion isotherme. Canadian Journal of Chemistry, 49,2636 (1971) IntroductionExperimental The thermodynamic and physical properties of alcohol-water mixtures have been studied extensively and are well reviewed by Franks and Ives ( 1 ) . In spite of the great deal of work performed on these systems doubt still remains as to the detailed interactions and structure present in these liquid mixtures. In two recent publications (2, 3), however, we have demonstrated that additional information on the structure of binary liquid systems may be obtained from an examination of the behavior of the energyvolume coefficient and cohesive energy density. In this paper we report detailed studies of the energy-volume coefficient and the cohesive energy density behavior of methyl alcohol -

“…[ll ( a u , av), = ~( a p , dT)p--p are being used increasingly in the study of binary liquid systems (1)(2)(3)(4)(5)(6)(7)(8)(9)(10). These parameters have proven useful in the investigation of structural changes in binary systerns as a function of composition, in addition to their important application for the derivation of excess functions of mixing at constant volume (1 1).…”

Section: Introductionmentioning

confidence: 99%

Excess energy–volume and cohesive energy density coefficients for binary systems. Comparison with constant pressure functions

Macdonald¹

1976

DIGBY D. MACDONALD. Can. J. Cheni. 54, 3559 (1976). Excess energy-volume and cohesive energy density coefficients have been calculated for the hexane 4-perfluoro-hexane, water + DMSO, water + rert-butanol, water f methanol, water + acetonitrile. and methanol + DMSO systems. These parameters are compared with other constant pressure excess functions of mixing for these binary systerns, and it is proposed that they represent additional criteria for the classification of liquid mixtures. [Traduit par le journal]