The Experts below are selected from a list of 66 Experts worldwide ranked by ideXlab platform
Yaşar Demirel - One of the best experts on this subject based on the ideXlab platform.
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Estimation of the Entropy of Vaporization at the normal boiling point for azeotropic mixtures containing water, alcohol or acetic acid
Thermochimica Acta, 1999Co-Authors: Yaşar DemirelAbstract:Abstract The Entropy of Vaporization at the normal boiling point has been estimated for binary and ternary azotropic mixtures containing water, alcohol or acetic acid. For this purpose, the Lee–Kesler correlation, developed originally for pure substances, is used with the appropriate mixing rules to estimate the heat of Vaporization of the mixtures. Estimations for the Entropy of Vaporization of the 97 binary and 78 ternary mixtures are expressed as function of the ratio of the normal boiling point to average molecular weight. These expressions predict the Entropy of Vaporization satisfactorily, with less than 5% average deviation.
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Estimation of the Entropy of Vaporization at the normal
Thermochimica Acta, 1999Co-Authors: Yaşar DemirelAbstract:The Entropy of Vaporization at the normal boiling point has been estimated for binary and ternary azotropic mixtures containing water, alcohol or acetic acid. For this purpose, the Lee±Kesler correlation, developed originally for pure substances, is used with the appropriate mixing rules to estimate the heat of Vaporization of the mixtures. Estimations for the Entropy of Vaporization of the 97 binary and 78 ternary mixtures are expressed as function of the ratio of the normal boiling point to average molecular weight. These expressions predict the Entropy of Vaporization satisfactorily, with less than 5% average deviation. # 1999 Elsevier Science B.V. All rights reserved.
Xingmin Zhao - One of the best experts on this subject based on the ideXlab platform.
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Modified group contribution method for predicting the Entropy of Vaporization at the normal boiling point
Industrial & Engineering Chemistry Research, 1993Co-Authors: Xingmin ZhaoAbstract:A new group contribution method has been proposed which only requires the molecular structure to predict the Entropy of Vaporization at the normal boiling point. The 483 compounds used to determine the group increments include a wide variety of organic substances. The average prediction error of the new method for these compounds is 1.4%. An extensive comparison has been made between the authors method and previously proposed techniques, and the results show that the new method has wider applicability and higher accuracy
Vlastimil Ruzicka - One of the best experts on this subject based on the ideXlab platform.
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estimation of the enthalpy of Vaporization and the Entropy of Vaporization for pure organic compounds at 298 15 k and at normal boiling temperature by a group contribution method
Industrial & Engineering Chemistry Research, 2005Co-Authors: Zdenka Kolska, Vlastimil RuzickaAbstract:A new group contribution method for estimating the enthalpy of Vaporization at 298.15 K (ΔHV(298.15 K)) and at the normal boiling temperature (ΔHV(Tb)), as well as the Entropy of Vaporization at the normal boiling temperature (ΔSV(Tb)), of pure organic compounds has been developed. Large databases of critically assessed data have been used for group contribution calculations: data for 831 compounds have been used for estimations at 298.15 K, and data for 589 compounds have been used for estimations at the normal boiling temperature. Values obtained by the method developed here have been compared with estimations by the Ducros, Chickos, and Ma and Zhao group contribution methods and by empirical equations by Vetere. A statistical analysis of the regressed data has been also performed, indicating the confidence of the regressed parameters and other related information. The average relative errors (ARE) for the new method are as follows: for ΔHV(298.15 K), 2.2%; for ΔHV(Tb), 2.6%; and for ΔSV(Tb), 1.8%. Th...
Zdenka Kolska - One of the best experts on this subject based on the ideXlab platform.
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estimation of the enthalpy of Vaporization and the Entropy of Vaporization for pure organic compounds at 298 15 k and at normal boiling temperature by a group contribution method
Industrial & Engineering Chemistry Research, 2005Co-Authors: Zdenka Kolska, Vlastimil RuzickaAbstract:A new group contribution method for estimating the enthalpy of Vaporization at 298.15 K (ΔHV(298.15 K)) and at the normal boiling temperature (ΔHV(Tb)), as well as the Entropy of Vaporization at the normal boiling temperature (ΔSV(Tb)), of pure organic compounds has been developed. Large databases of critically assessed data have been used for group contribution calculations: data for 831 compounds have been used for estimations at 298.15 K, and data for 589 compounds have been used for estimations at the normal boiling temperature. Values obtained by the method developed here have been compared with estimations by the Ducros, Chickos, and Ma and Zhao group contribution methods and by empirical equations by Vetere. A statistical analysis of the regressed data has been also performed, indicating the confidence of the regressed parameters and other related information. The average relative errors (ARE) for the new method are as follows: for ΔHV(298.15 K), 2.2%; for ΔHV(Tb), 2.6%; and for ΔSV(Tb), 1.8%. Th...
William E Acree - One of the best experts on this subject based on the ideXlab platform.
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calculation of the vapour pressure of organic molecules by means of a group additivity method and their resultant gibbs free energy and Entropy of Vaporization at 298 15 k
Molecules, 2021Co-Authors: Rudolf Naef, William E AcreeAbstract:The calculation of the vapour pressure of organic molecules at 298.15 K is presented using a commonly applicable computer algorithm based on the group-additivity method. The basic principle of this method rests on the complete breakdown of the molecules into their constituting atoms, further characterized by their immediate neighbour atoms. The group contributions are calculated by means of a fast Gauss-Seidel fitting algorithm using the experimental data of 2036 molecules from literature. A ten-fold cross-validation procedure has been carried out to test the applicability of this method, which confirmed excellent quality for the prediction of the vapour pressure, expressed in log(pa), with a cross-validated correlation coefficient Q2 of 0.9938 and a standard deviation σ of 0.26. Based on these data, the molecules' standard Gibbs free energy ΔG°vap has been calculated. Furthermore, using their enthalpies of Vaporization, predicted by an analogous group-additivity approach published earlier, the standard Entropy of Vaporization ΔS°vap has been determined and compared with experimental data of 1129 molecules, exhibiting excellent conformance with a correlation coefficient R2 of 0.9598, a standard error σ of 8.14 J/mol/K and a medium absolute deviation of 4.68%.