摘要:

Partial radial distribution functions of binary hard sphere systems with strong size difference between the constituting atoms are calculated starting from the Percus-Yevick equation. Partial coordination numbers of nearest neighbours are defined. Empirical relations are found which give partial coordination numbers of an accuracy better than 1 % as a function of packing fraction (0.2 ±n ±0.5), size difference([sgrave]2/[sgrave]1±1.44) and composition. Introduction of pairwise interactions between nearest neighbours yields for the enthalpy of mixing approximately the same composition dependence as given by the Flory-Huggins equation, and explains why the numerical value of the “interchange energy” depends on the choice of indexing the constituents.

ISSN:0031-9104    

DOI:10.1080/00319108808078572

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The solubility of salt in water decreases in the presence of a water soluble polymer, polyethylene glycol (PEG), and could be expressed by a linear relationship between the logarithm of the solubility of salt (M) and the concentration of PEG (M). The slope of the solubility lines was in agreement with the excluded volume of PEG calculated with the rod-like model of PEG. The solubility limit of each salt in the PEG-free solvent (solvent unoccupied by PEG) remained constant regardless of the concentration of PEG. Therefore, the solubility of salt in PEG solutions may be described by the excluded volume effects of PEG. This suggests that PEG sterically excludes salt, thus salt is concentrated in the accessible solvent up to the solubility limit.

ISSN:0031-9104    

DOI:10.1080/00319108808078573

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Reliable viscosities and molar volumes are reported for some binary and ternary liquid mixtures containing carbon tetrachloride, tetrachloroethylene, benzene, toluene and pyridine. Similarities are observed in the shapes of the viscosity and vapor pressure curves for the binary systems. Systems exhibiting linear vapor pressure vs. mole fraction curves also exhibit, with some exceptions, linear viscosity vs. mole fraction curves. Maxima and minima found for some systems on the vapor pressure vs. mole fraction curves are often observed on the viscosity vs. mole fraction curves. This is especially true for systems containing species close in viscosity values. The viscosity vs. mole fraction data for the binary systems are well correlated with a modified Katti-Heric equation. One ternary constant, in addition to the respective binary system constants, predicts the viscosities of ternary systems well.

ISSN:0031-9104    

DOI:10.1080/00319108808078574

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Neutron diffraction experiments have been made on molten alloys Mn67.4Cu32.6and Mn62.6Sn37.4which have the “null-matrix” composition. The scattered intensity distributions for these alloys have been corrected for paramagnetic neutron scattering and they then relate to composition fluctuations alone. They have been analysed to yield the Radial Concentration Function (RCF). The RCFs for both alloys give a clear indication of true short range order—a preference for unlike first neighbours. The curves are discussed in terms of expected first neighbour distances and the atomic correlations in the stable crystalline phases. Comparison is also made between the values of the chemical short range order parameter a, estimated from the RCFs and the measured values of the enthalpy of mixing AH.

ISSN:0031-9104    

DOI:10.1080/00319108808078575

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Transference numbers and mean ionic activity coefficients of solutions of potassium chloride and sodium chloride in glycerol have been measured at 25°C using concentration cells with silver/silver chloride electrodes. The EMFs of cells with transference, using a liquid junction, were measured at concentrations between 0.001 and 0.5 mol dm−3, and the EMFs of cells without transference were measured using a potassium or sodium amalgam to link the two half-cells, at concentrations in the range 0.05 to 0.5 mol dm−3. Using the Nernst equations, cation transference numbers of 0.479 and 0.417 were deduced respectively for solutions of potassium chloride and sodium chloride in glycerol at a concentration of 0.1 mol dm−3. Activity coefficients for both salts were deduced as a function of concentration up to 0.5 mol dm−3, using independent data on the low concentration transference numbers. The results indicate similarities between the solvent properties of glycerol and water.

ISSN:0031-9104    

DOI:10.1080/00319108808078576

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

We have calculated the Bhatia-Thornton partial structure factors for a two component system of charged hard spheres in solution, using the mean spherical approximation for the computation of the Ashcroft-Langreth structure factors. Our results show that for electrolytes which are highly asymmetrical in size and charge, the charge-number partial structure factorSNQ(q)is very sensitive to the distribution of the ions. The Bhatia-Thornton structure factors exhibit clearly the effects of charge ordering and condensation of the small ions around the large ions in concentated solutions.

ISSN:0031-9104    

DOI:10.1080/00319108808078577

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The mean square dipole moments of 1:1 complexes of n-butanol,i-butanol and r-butanol with aniline and pyridine in benzene are determined following two different methods: one uses Onsager's method based on dipole-dipole interaction and the other uses the help of modified Palit's method involving a limiting polarization measurement technique. The interaction dipole moments Δμ for the thermodynamically most favoured geometry of 1:1 complexes of the system involving butanol-aniline and butanol-pyridine were calculated. The value of Δμ indicated that complexation is due to polarization interaction. Furthermore, Δμ is found to be in the order pyridine > aniline. The dipole moment of the complexes involving butanol-aniline and butanol-pyridine is found to be in the order pyridine > aniline. These results have been used in interpreting of the structures of the complexes.

ISSN:0031-9104    

DOI:10.1080/00319108808078578

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Excess volumes for binary liquid mixtures of N, N-dimethylformamide andN, N-dimethylacetamide with ethylacetate,n-propylacetaten-butylacetate, iso-propylacetate and iso-amylacetate have been measured at 303.15 K. Excess volumes are negative in all the systems over the entire range of composition. The results have been discussed in terms of specific interactions between like and unlike molecules and the difference in size and shape of the component molecules.

ISSN:0031-9104    

DOI:10.1080/00319108808078579

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Isobaric boiling point data for systems of 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, and sec-butanol have been measured over the whole composition range at 300, 500 and 700 mmHg. The experimentalt-xdata have been used to predict Wilson parameters and equilibrium vapor compositions. The parameters are in turn used to predict activity coefficients and excess Gibbs free energies for these systems over the entire composition range. The values ofGEare positive in the systems at all pressures studied.

ISSN:0031-9104    

DOI:10.1080/00319108808078580

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0031-9104    

DOI:10.1080/00319108808078571

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor