Thermodynamic properties of alcohol solutions. II. Ethanol and isopropanol systems

1956 ◽  
Vol 9 (3) ◽  
pp. 364 ◽  
Author(s):  
I Brown ◽  
W Fock ◽  
F Smith
Keyword(s):  
Experimental Data ◽  
Free Energy ◽  
Thermodynamic Properties ◽  
Excess Entropy ◽  
Excess Free Energy ◽  
Published Data ◽  
Entropy Of Mixing ◽  
Heats Of Mixing ◽  
Equilibrium Data

New experimental data are given for the heats of mixing of the systems ethanol+toluene at 35 �C, ethanol+methylcyclohexane at 35 �C, and iso-propanol+benzene at 45 �C and for the liquid-vapour equilibrium data for the latter system at 45 �C. These data have been used together with previously published data to calculate the excess free energy, heat and excess entropy of mixing at even mole fractions for the above systems. These functions have also been calculated from published data for the systems ethanol+benzene at 45 �C and ethanol+2,2,4-trimethylpentane at 25 �C.

Heats of mixing. II. Acetonitrile and nitromethane systems

1956 ◽  
Vol 9 (2) ◽  
pp. 180 ◽  
Author(s):  
I Brown ◽  
W Fock
Keyword(s):  
Free Energy ◽  
Carbon Tetrachloride ◽  
Composition Range ◽  
Excess Entropy ◽  
Excess Free Energy ◽  
Energy Data ◽  
Entropy Of Mixing ◽  
Heats Of Mixing

The heats of mixing at 45.00 �C have been measured at intervals over the whole composition range for the systems : acetonitrile+carbon tetrachloride, acetonitrile+benzene, acetonitrile +nitromethane, nitromethane + carbon tetrachloride, and nitromethane+benzene. These data, together with the excess free energy data of Brown and Smith (1954, 1955a, 1955b), have been used to calculate the excess entropy of mixing for these systems.

Excess thermodynamic properties of the liquid system acetone + methyl iodide

1964 ◽  
Vol 281 (1386) ◽  
pp. 366-376 ◽  
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Methyl Iodide ◽  
Excess Entropy ◽  
Heat Content ◽  
Liquid Mixtures ◽  
Liquid System ◽  
Excess Thermodynamic Properties ◽  
Temperature Range ◽  
Entropy Of Mixing

The increase in heat content attending the isobaric formation of liquid mixtures of acetone and methyl iodide in varying proportions has been determined calorimetrically in the temperature range 253 to 308 °K. The corresponding change in free energy has been measured from analyses of the mixed vapour at equilibrium with the mixed liquids. By difference, the change in entropy associated with the mixing has been found. Most of this derives, as is usual, from the randomness of the mixture, but there is a relatively small residuum (the so-called excess entropy of mixing) which is found to vary in an unusual way with respect to the composition.

scholarly journals Kinetics and thermodynamic properties related to the drying of 'Cabacinha' pepper fruits

2016 ◽  
Vol 20 (2) ◽  
pp. 174-180 ◽  
Author(s):  
Hellismar W. da Silva ◽  
Renato S. Rodovalho ◽  
Marya F. Velasco ◽  
Camila F. Silva ◽  
Luís S. R. Vale
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Free Energy ◽  
Thermodynamic Properties ◽  
Gibbs Free Energy ◽  
Removal Rate ◽  
Effective Diffusion ◽  
Drying Time ◽  
Three Samples ◽  
Different Temperatures

ABSTRACT The objective of this study was to determine and model the drying kinetics of 'Cabacinha' pepper fruits at different temperatures of the drying air, as well as obtain the thermodynamic properties involved in the drying process of the product. Drying was carried out under controlled conductions of temperature (60, 70, 80, 90 and 100 °C) using three samples of 130 g of fruit, which were weighed periodically until constant mass. The experimental data were adjusted to different mathematical models often used in the representation of fruit drying. Effective diffusion coefficients, calculated from the mathematical model of liquid diffusion, were used to obtain activation energy, enthalpy, entropy and Gibbs free energy. The Midilli model showed the best fit to the experimental data of drying of 'Cabacinha' pepper fruits. The increase in drying temperature promoted an increase in water removal rate, effective diffusion coefficient and Gibbs free energy, besides a reduction in fruit drying time and in the values of entropy and enthalpy. The activation energy for the drying of pepper fruits was 36.09 kJ mol-1.

scholarly journals Adsorption Equilibrium of 1, 1-Dichloro-1-fluoroethane (HCFC-141b) on a Hydrophobic Zeolite

1998 ◽  
Vol 16 (2) ◽  
pp. 67-75 ◽  
Author(s):  
Wen-Tien Tsai ◽  
Ching-Yuan Chang ◽  
Chih-Yin Ho
Keyword(s):  
Experimental Data ◽  
Free Energy ◽  
Thermodynamic Properties ◽  
Adsorption Isotherms ◽  
Ozone Depletion ◽  
Adsorption Equilibrium ◽  
Stratospheric Ozone ◽  
Stratospheric Ozone Depletion ◽  
Equilibrium Isotherms ◽  
Entropy Of Adsorption

Of the major replacements for chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) are now accepted as being prime contributors to stratospheric ozone depletion. As a consequence, the development of adsorbents capable of adsorbing and recovering specific HCFCs has received great attention. This paper describes an investigation of the adsorption equilibrium of 1, 1-dichloro-1-fluoroethane (HCFC-141b) vapour on a commercial hydrophobic zeolite. The corresponding Henry, Freundlich and Dubinin–Radushkevich (D–R) equilibrium isotherms have been determined and found to correlate well with the experimental data. Based on the Henry adsorption isotherms obtained at 283, 303 and 313 K. thermodynamic properties such as the enthalpy, free energy and entropy of adsorption have been computed for the adsorption of HCFC-141b vapour on the adsorbent. The results obtained could be useful in the application of HCFC adsorption on the hydrophobic zeolite studied.

The rubidium chloride – sodium chloride phase diagram

1970 ◽  
Vol 48 (22) ◽  
pp. 3483-3486 ◽  
Author(s):  
A. D. Pelton ◽  
S. N. Flengas
Keyword(s):  
Phase Diagram ◽  
Free Energy ◽  
Sodium Chloride ◽  
Excess Entropy ◽  
Excess Free Energy ◽  
Thermochemical Data ◽  
Cooling Curves ◽  
Molar Excess ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing

The phase diagram of the RbCl–NaCl system has been measured by the method of cooling curves. By combining these data with available thermochemical data for the system, the integral molar excess free energy of mixing at 800 °C has been calculated as ΔGE = −632XRbClXNaCl cal/mole; and the integral molar excess entropy of mixing has been calculated as ΔSE = −0.208XRbClXNaCl cal/°K mole. Estimated precisions are ±50 cal for ΔGE and ±0.05 cal/°K mole for ΔSE at XRbCl = XNaCl = 0.5.

scholarly journals Friedman’s excess free energy and the McMillan–Mayer theory of solutions: Thermodynamics

2012 ◽  
Vol 85 (1) ◽  
pp. 105-113
Author(s):  
Juan Luis Gómez-Estévez
Keyword(s):  
Experimental Data ◽  
Free Energy ◽  
Canonical Ensemble ◽  
Excess Free Energy ◽  
Grand Canonical Ensemble ◽  
Virial Expansion ◽  
Multicomponent Systems ◽  
Real Gas ◽  
Precise Meaning ◽  
Grand Canonical

In his version of the theory of multicomponent systems, Friedman used the analogy which exists between the virial expansion for the osmotic pressure obtained from the McMillan–Mayer (MM) theory of solutions in the grand canonical ensemble and the virial expansion for the pressure of a real gas. For the calculation of the thermodynamic properties of the solution, Friedman proposed a definition for the “excess free energy” that is a reminder of the ancient idea for the “osmotic work”. However, the precise meaning to be attached to his free energy is, within other reasons, not well defined because in osmotic equilibrium the solution is not a closed system and for a given process the total amount of solvent in the solution varies. In this paper, an analysis based on thermodynamics is presented in order to obtain the exact and precise definition for Friedman’s excess free energy and its use in the comparison with the experimental data.

Volume Changes on Mixing. II. Systems Containing Acetone, Acetonitrile, and Nitromethane

1962 ◽  
Vol 15 (1) ◽  
pp. 9 ◽  
Author(s):  
I Brown ◽  
F Smith
Keyword(s):  
Concentration Dependence ◽  
Binary Systems ◽  
Excess Entropy ◽  
Volume Changes ◽  
Polar Components ◽  
Entropy Changes ◽  
Heats Of Mixing ◽  
Equilibrium Data

The volume changes on mixing have been measured at 25, 35, and 45 �C for the following binary systems : acetone+acetonitrile, acetone+nitromethane, acetonitrile+nitromethane and each of these polar components with benzene and with carbon tetrachloride.The sign and concentration dependence of the volume changes on mixing of these systems follow closely the excess entropy changes on mixing calculated from the liquid-vapour equilibrium data and heats of mixing previously measured in these laboratories.

Liquid-vapour equilibria. VII. The systems nitromethane + benzene and nitromethane + carbon tetrachloride at 45°C

1955 ◽  
Vol 8 (4) ◽  
pp. 501
Author(s):  
I Brown ◽  
F Smith
Keyword(s):  
Free Energy ◽  
Carbon Tetrachloride ◽  
Excess Free Energy ◽  
Energy Of Mixing ◽  
Equilibrium Data ◽  
Free Energy Of Mixing

The liquid-vapour equilibrium data are given for the systems nitromethane+benzene and nitromethane+carbon tetrachloride at 45.00 �C. These data are used to calculate the excess free energy of mixing for these systems.

Study of the water-bentonite system by vapour adsorption, immersion calorimetry and X-ray techniques: II. Heats of immersion, swelling pressures and thermodynamic properties

Clay Minerals ◽  
1990 ◽  
Vol 25 (4) ◽  
pp. 499-506 ◽  
Author(s):  
G. Kahr ◽  
F. Kraehenbuehl ◽  
H. F. Stoeckli ◽  
M. Müller-Vonmoos
Keyword(s):  
Experimental Data ◽  
Free Energy ◽  
Thermodynamic Properties ◽  
Adsorption Isotherms ◽  
Water Adsorption ◽  
Immersion Calorimetry ◽  
X Ray ◽  
Vapour Adsorption ◽  
Heats Of Immersion

AbstractA number of thermodynamic properties were obtained from the determination of adsorption isotherms and enthalpies of immersion for systems with water and Na- and Ca-bentonites. Entropy differences were calculated by combining the enthalpies of immersion and the changes in free energy derived from the adsorption isotherms. The swelling pressures, also calculated from the water adsorption isotherms, are in satisfactory agreement with the experimental data.

Sign in / Sign up

Export Citation Format

Share Document