Osamu Kiyohara

Evaluation of excess isentropic compressibilities and isochoric heat capacities

Abstract Two approximations commonly used to evaluate the ideal contribution to excess isentropic compressibilities and to excess isochoric heat capacities are compared for several binary mixtures.

Thermodynamics of aqueous mixtures of nonelectrolytes. I. Excess volumes of water-n-alcohol mixtures at several temperatures

Excess volumes of binary mixtures of water with methanol, ethanol and 1-propanol were obtained from density measurements at 5 degree intervals from 15 to 35°C over the entire composition range. Excess thermal expansion coefficients, partial molar excess volumes, and expansibilities at 25°C were derived from the results. The significance of these values is discussed in relation to hypothesized structural changes in the mixtures.

Ultrasonic speeds and isentropic compressibilities of n-alkanol + n-heptane mixtures at 298.15 K☆

Abstract Measurements of ultrasonic speeds were made for binary mixtures of the n -alkanols C 1 to C 6 , C 8 and C 10 with n -heptane over the whole mole fraction range at 298.15 K. Detailed studies were also carried out at high dilutions of the n -alkanols and of n -heptane. Excess isentropic compressibilities ϰ S E were derived from the results. The general pattern of the ϰ S E curves for the series of mixtures is similar to that found previously for their molar excess volumes. However, the ϰ S E curves for the longer n -alkanols exhibit a noticeable tendency to develop a point of inflexion at high alkanol dilutions.

Excess volumes for n-alkanols +n-alkanes IV. Binary mixtures of decan-1-ol +n-pentane, +n-hexane, +n-octane, +n-decane, and +n-hexadecane☆

Abstract Excess volumes measured at 298.15 K in a successive-dilution dilatometer are reported for binary mixtures of decan-l-ol with the n-alkanes C5, C6, C8, C10, and C16. The measurements were extended to high dilutions of decan-1-ol. The excess volume is negative over the whole mole-fraction range for the C5 mixture, sigmoid with increasingly positive values in the alkane-rich region for C6, C8, and C10 mixtures, and positive over the whole mole-fraction range for the C16 mixture. Partial molar excess volumes of the components were calculated for each mixture, and their values at infinite dilution were estimated. The excess volumes of these mixtures are attributed to a balance between chemical, physical, and structural effects.

Thermodynamics of aqueous mixtures of nonelectrolytes II. Isobaric heat capacities of water-n-alcohol mixtures at 25°C

Excess isobaric heat capacities of binary mixtures of water with methanol, ethanol, and 1-propanol were obtained from flow microcalorimetric measurements at 25°C over the entire composition range. The results are compared with those of previous investigations.

Thermodynamic properties of binary mixtures containing ketones I. Excess enthalpies of some aliphatic ketones + n-hexane, + benzene, and + tetrachloromethane

Abstract Flow-calorimetric measurements of excess enthalpies at 298.15 K are reported for mixtures of 2-butanone + n -hexane, + benzene, + tetrachloromethane, and of 2-pentanone and 3-pentanone with the same set of second components. The results indicate that important interactions occur between the ketoxy group and benzene and tetrachloromethane.

Ultrasonic velocities, compressibilities, and heat capacities for binary mixtures of benzene, cyclohexane, and tetrachloromethane at 298.15 K☆

Abstract Ultrasonic velocities in binary mixtures of benzene, cyclohexane, and tetrachloromethane were determined at 298.15 K over the whole mole fraction range using a pulse-echooverlap method in a successive dilution cell. The results were combined with auxiliary information from the literature to obtain isentropic and isothermal compressibilities, and heat capacities at constant volume. The excess values of these properties are compared with previously published results.

Thermodynamic properties of binary mixtures containing esters. I. Analysis of the properties of n-alkanoate + n-alkane and n-alkanoate + n-alkanoate mixtures in terms of a quasichemical group-contribution model

Abstract The thermodynamic properties of n-alkanoate + n-alkane and + n-alkanoate binary liquid mixtures are examined on the basis of the group-surface interaction version of the Guggenheim-Barker quasichemical pseudolattice theory. All the data available in the literature for liquid—vapor and liquid—liquid equilibria, excess enthalpies and activity coefficients at infinite dilution are taken into consideration. Using only four alkyl-group increments, in addition to the two group-interaction parameters for methyl ethanoate, the model provides a fairly consistent description of the properties of the mixtures as functions of composition, temperature and chain length. The results are discussed in comparison with other classes of systems investigated previously (alkanones and alkanals).

Thermodynamics of aqueous mixtures of nonelectrolytes. III. Compressibilities and isochoric heat capacities of water-n-alcohol mixtures at 25°C

Speeds of ultrasound in binary mixtures of water with methanol, ethanol, and 1-propanol were measured at 25°C over the whole composition range by a pulseecho-overlap method. Excess isentropic compressibilities, excess isothermal compressibilities and excess isochoric heat capacities were derived from the results in combination with the results of our previous studies of thermal expansibilities and isobaric heat capacities.

Thermodynamic properties of binary mixtures containing ketones III. Excess enthalpies of n-alkanes + some aliphatic ketones

Abstract Flow-calorimetric measurements of excess enthalpies at 298.15 K are reported for n -pentane + 2-butanone, + 2-pentanone, and +3-pentanone, and for n -heptane, n -octane, and n -decane with each of the same set of aliphatic ketones.