Notizen: Diffusion in the Liquid System Chloroform + Methyl Acetate

1986 ◽  
Vol 41 (11) ◽  
pp. 1337-1338 ◽  
Author(s):  
R. Haase ◽  
W. Engels
Keyword(s):  
Diffusion Coefficient ◽  
Mole Fraction ◽  
Activity Coefficients ◽  
Linear Relation ◽  
Methyl Acetate ◽  
Composition Dependence ◽  
Liquid System ◽  
C 30

We present and discuss the results of measurements of the diffusion coefficient D and the activity coefficients as functions of the mole fraction x of one of the components in the liquid system chloroform + methyl acetate at 10 °C, 30 °C, and 50 °C. The function D(x) exhibits a pronounced maximum at each temperature, while the kinematic diffusion coefficient D*, considered as function of x, shows a flat minimum, its composition dependence being nearer to a linear relation than that of D(x).

scholarly journals Verdampfungsgleichgewicht und thermodynamisehe Funktionen des flüssigen Systems Wasser + Essigsäure / Vapour-Liquid. Equilibrium and Thermodynamic Functions of the Liquid System Water + Acetic Acid

1973 ◽  
Vol 28 (10) ◽  
pp. 1740-1742 ◽  
Author(s):  
R. Haase ◽  
M. Pehlke ◽  
K.-H. Dücker
Keyword(s):  
Acetic Acid ◽  
Composition Dependence ◽  
Excess Enthalpy ◽  
Excess Entropy ◽  
Liquid System ◽  
Gibbs Function ◽  
Liquid Equilibrium ◽  
Molar Excess ◽  
C 30 ◽  
System Water

Vapour pressures and vapour compositions of the liquid system water + acetic acid have been measured at 25 °C, 30 °C, 35 °C, 40 °C, and 45 °C in the whole range of compositions. The dimerization of acetic acid in the vapour being taken into account, the molar excess Gibbs function ḠE is derived from the measurements. Earlier measurements of the molar excess enthalpy HE are combined with the -GE values to give the molar excess entropy SE. The “symmetry rule” (Haase, 1951) concerning the composition dependence of ḠE, -HE, and S̄E has been confirmed.

Thermodynamic Excess Functions for the Liquid System W ater + Acetic Acid from Calorimetric Data

1977 ◽  
Vol 32 (5) ◽  
pp. 507-510 ◽  
Author(s):  
R. Haase ◽  
M. Pehlke
Keyword(s):  
Acetic Acid ◽  
Composition Dependence ◽  
Liquid System ◽  
Pure Liquid ◽  
Excess Functions ◽  
Molar Excess ◽  
Molar Excess Volume ◽  
Thermodynamic Excess Functions ◽  
C 30 ◽  
System Water

Abstract For the liquid system water + acetic acid, we give the results of new calorimetric measurements regarding the molar excess enthalpy H̅E for 25 °C, 30 °C, 35 °C, 40 °C, 55 °C, and 70 °C, covering nearly the entire range of com­ positions. The experimental data show that H̅E is positive for all compositions and temperatures except in the region of low acid concentrations at temperatures below 55 °C where the process of mixing the pure liquid components is exothermic (H̅E<0). Using values of the molar excess Gibbs function G̅E (always positive) derived from earlier data on vapour-liquid equilibria, we compute the molar ex­cess entropy S̅E which is always negative. The “symmetryrule” concerning the composition dependence of G̅E (as compared to that of H̅E and S̅E) has again been confirmed. The composition dependence of S̅E is similar to that of the molar excess volume.

Enthalpies of Mixing for the Liquid System Formic Acid + Acetic Acid

1979 ◽  
Vol 34 (5) ◽  
pp. 659-660
Author(s):  
R. Haase ◽  
H.-J. Jansen ◽  
K. Puder ◽  
B. Winter
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Mole Fraction ◽  
Excess Enthalpy ◽  
Liquid System ◽  
Short Description ◽  
Enthalpies Of Mixing ◽  
Calorimetric Measurements ◽  
C 30 ◽  
Increasing Temperature

Abstract After a short description of the evaluation of the calorimetric measurements, we give the results for the enthalpies of mixing in the liquid system formic acid + acetic acid. The molar excess enthalpy H̄E has been determined as a function of the mole fraction x of acetic acid at 18 °C, 20 °C, 25 °C, 30 °C, and 40 °C. The function H̄E (x) is always positive and nearly symmetric (with a maximum at about x = 0.5) and increases with increasing temperature. A three-parameter fit of the function H̄E (x) has been achieved for each temperature.

Diffusion in Non-ideal Liquid Mixtures

1983 ◽  
Vol 38 (2) ◽  
pp. 281-284 ◽  
Author(s):  
R. Haase ◽  
W. Engels
Keyword(s):  
Diffusion Coefficient ◽  
Carbon Tetrachloride ◽  
Mole Fraction ◽  
Entire Range ◽  
Ideal Liquid ◽  
Liquid Mixtures ◽  
Liquid System ◽  
Nonelectrolyte Solution ◽  
Straight Line ◽  
The Difference

Abstract An equation proposed recently (Haase and Jansen, 1980) relates to the dependence on composition and temperature of the diffusion coefficient D and of the kinematic diffusion coefficient D* in a binary nonelectrolyte solution. This equation is now applied to our own measurements of the activity coefficients and of the diffusion coefficient in the non-ideal liquid system carbon tetrachloride + acetone at 20 °C and 40 °C over the entire range of compositions. (For 0 °C only values of D are available.) It turns out that the function D (x), where x denotes the mole fraction of one of the components, exhibits a minimum at each temperature, while D* (x) nearly represents a straight line. We establish a correlation between the deviations from Raoult's Law and the sign of the difference D - D*.

scholarly journals Notizen:Mischungsenthalpien beim flüssigen System Wasser + Essigsäure / Heats of Mixing for the Liquid System Water + Acetic Acid

1972 ◽  
Vol 27 (10) ◽  
pp. 1527-1529 ◽  
Author(s):  
R. Haase ◽  
P. Steinmetz ◽  
K.-H. Dücker
Keyword(s):  
Acetic Acid ◽  
Power Series ◽  
Liquid System ◽  
Heat Of Mixing ◽  
Pure Liquid ◽  
Calorimetric Measurements ◽  
Heats Of Mixing ◽  
Free Parameters ◽  
C 30 ◽  
System Water

Calorimetric measurements of the heats of mixing for the liquid system water+acetic acid at 17 °C, 20 °C, 25 °C, 30 °C, 40 °C, and 50 °C show that there is a change of sign in the function H̅E(x), where H̅E denotes the molar heat of mixing and x the mole fraction of acetic acid. The process of mixing the pure liquid components is weakly exothermic for low acid concentrations, but strongly endothermic for high acid concentrations. The function H̅E can be approximately represented by the usual power series with respect to x, five free parameters at each temperature being necessary.

scholarly journals Segmental Modification of the Mualem Model by Remolded Loess

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Le-fan Wang ◽  
Xing-zhong Weng ◽  
Zhi-hua Yao ◽  
Ren-yi Zhang ◽  
Wan Li ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Linear Relation ◽  
Goodness Of Fit ◽  
Characteristic Curve ◽  
Variable Parameter ◽  
Dry Density ◽  
Parameter Method ◽  
Test Results ◽  
Segmentation Method ◽  
Through Diffusion

The measured diffusion coefficient and soil-water characteristic curve (SWCC) of remolded loess were used to modify the Mualem model for increasing its accuracy. The obtained results show that the goodness of fit between the Mualem model and the variable parameter-modified Mualem method comparing with the test results was not high. The saturation of 0.65 was introduced as the boundary to divide the curve of the measured diffusion coefficient into two segments. When the segmentation method combined with the variable parameter method was used to modify the Mualem model, the fitting correlation coefficient was increased to 0.921–0.998. The modified parameters Ko and L corresponding to remolded loess were calculated for different dry densities. Based on the exponential function between Ko and dry density and the linear relation between L and dry density, the segmentally modified Mualem model was established for remolded loess by considering variation in dry density. The results of the study can be used for directly determining the unsaturated infiltration coefficient and for indirectly determining the SWCC through diffusion coefficient.

The Concentration Dependence at 1 atm Pressure and 300 °K of the Binary Diffusion Coefficients of the Systems Helium – Carbon Dioxide, Helium – Nitrous Oxide, and Helium – Sulfur Hexafluoride

1972 ◽  
Vol 50 (12) ◽  
pp. 1874-1876 ◽  
Author(s):  
Kenneth R. Harris ◽  
T. N. Bell ◽  
Peter J. Dunlop
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Diffusion Coefficient ◽  
Concentration Dependence ◽  
Mole Fraction ◽  
Diffusion Coefficients ◽  
Sulfur Hexafluoride ◽  
Enskog Theory ◽  
Binary Diffusion ◽  
Binary Diffusion Coefficients

Binary diffusion coefficients are reported for the systems He–CO2, He–N2O, and He–SF6. In agreement with the Chapman–Enskog theory the concentration dependence of the diffusion coefficient of each system increases with the mole fraction of the heavier component.

Activity Coefficients and Excess Molar Gibbs Functions of Liquid Alkali Halide + Silver Halide Mixtures at Varying Temperature and Composition

1981 ◽  
Vol 36 (10) ◽  
pp. 1100-1105
Author(s):  
J. Richter ◽  
R. Conradt ◽  
R. Becker
Keyword(s):  
Molten Salt ◽  
Mole Fraction ◽  
Activity Coefficients ◽  
Salt Concentration ◽  
Alkali Halide ◽  
Silver Halide ◽  
Thermodynamic Factor ◽  
Gibbs Function ◽  
Temperature Ranges ◽  
Concentration Cells

In certain temperature ranges, the e.m.f. of binary molten salt concentration cells without transference can be described by a mole fraction expansion with three constants depending linearly on temperature.With the six constants it is possible to calculate the activity coefficients, the thermodynamic factor, and the excess molar Gibbs function of liquid alkali halide + silver halide mixtures at given temperatures and compositions. The precision of the representation corresponds to an accuracy in the e.m.f. data of 0.5 mV to 1.2 mV.

Sign in / Sign up

Export Citation Format

Share Document