Excess molar volumes and isentropic compressibilities of binary liquid mixtures containing n-alkanes at 298.15 K

Pramana (Impact Factor: 0.56). 01/2002; 59(4):663-670. DOI: 10.1007/s12043-002-0076-6

ABSTRACT Excess molar volumes (V
E) and deviation in isentropic compressibilities (Δβ
s) have been investigated from the density ρ and speed of sound u measurements of six binary liquid mixtures containing n-alkanes over the entire range of composition at 298.15 K. Excess
molar volume exhibits inversion in sign in one binary mixture, i.e., n-heptane + n-hexane. Remaining five binary mixtures,
n-heptane + toluene, cyclohexane + n-heptane, cyclohexane + n-hexane, toluene + n-hexane and n-decane + n-hexane show negative
excess molar volumes over the whole composition range. However, the large negative values of excess molar volume becomes domainant
in toluene + n-hexane mixture. Deviation in isentropic compressibility is negative over the whole range of composition in
the case of all the six binary mixtures. Existence of specific intermolecular interactions in the mixtures has been analyzed
in terms of excess molar volume and deviation in isentropic compressibility.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Experimental densities (ρ), viscosities (η), and speeds of sound (u) of the binary mixtures of n-dodecane with an alkan-1-ol (hexan-1-ol, heptan-1-ol, octan-1-ol) or an alkan-2-ol (hexan-2-ol, heptan-2-ol and octan-2-ol) were measured over the whole mixture composition range at T = 298.15 K. From these data, the excess molar volume ( $ V_{\text{m}}^{\text{E}} $ V m E ), deviations in viscosity (Δη), and excess isentropic compressibility ( $ \kappa_{S}^{\text{E}} $ κ S E ) have been calculated. The results were fitted by means of the Redlich–Kister equation, in order to estimate the binary coefficients and standard errors. Differences among these binary systems are ascribed to the different association abilities of the alkan-1-ols and alkan-2-ols. Experimental data on the constituted binaries were analyzed using McAllister’s multi-body interaction model, the Jouyban–Acree model, the Prigogine–Flory–Patterson theory, and the Bloomfield and Dewan model. The experimental and calculated quantities are used to study the nature of mixing behavior among the mixtures.
    Journal of Solution Chemistry 42(6). · 1.13 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The densities of the (cyclohexane + pentane, or hexane, or heptane, or octane, or nonane) systems were measured at the temperature 298.15 K by means of a vibrating-tube densimeter. Their respective excess molar volumes were calculated and correlated using the fourth-order Redlich—Kister equation, with the maximum likelihood principle being applied in the determination of the adjustable parameters. The values of excess molar volumes were negative for the cyclohexane + pentane system, whereas they were positive for the other systems with the values increasing with the number of carbon atoms in the respective alkane molecules.
    Chemical Papers- Slovak Academy of Sciences 01/2007; 61(6):497-501. · 0.88 Impact Factor


Available from