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Joao Carlos R Reis - One of the best experts on this subject based on the ideXlab platform.
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The two faces of the Redlich–Kister equation and the limiting partial Molar volume of water in 1-aminopropan-2-ol
Thermochimica Acta, 2008Co-Authors: Jaime D. Gomes De Oliveira, Joao Carlos R ReisAbstract:Abstract The properties of the Redlich–Kister equation when expressed in power series of x1 − x2 are related to its alternative expression in terms of power series of x2 − x1, where x1 and x2 are mole fractions of the components 1 and 2 of a binary liquid mixture. The simple relationship between both sets of coefficients is derived and shown to conceal pitfalls while using Redlich–Kister coefficients to estimate partial Molar properties of the components. The zero-powered terms, which are the same for the alternative expansions, are shown to yield four-fold the excess Molar Property for the equiMolar mixture. Literature data for the partial Molar volume of water at infinite dilution in 15 neat aminoalkanols at different temperatures are collected and tabulated. These data generally show a positive dependence of that limiting value on the temperature, the only apparent exception being in the case of 1-aminopropan-2-ol. It is demonstrated that the recently published data for this aminoalkanol [S. Mokraoui, A. Valtz, C. Coquelet, D. Richon, Thermochim. Acta 440 (2006) 122–128] were ill-treated and recalculated limiting values are given, which increase with increasing temperature.
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the two faces of the redlich kister equation and the limiting partial Molar volume of water in 1 aminopropan 2 ol
Thermochimica Acta, 2008Co-Authors: Jaime Gomes D De Oliveira, Joao Carlos R ReisAbstract:Abstract The properties of the Redlich–Kister equation when expressed in power series of x1 − x2 are related to its alternative expression in terms of power series of x2 − x1, where x1 and x2 are mole fractions of the components 1 and 2 of a binary liquid mixture. The simple relationship between both sets of coefficients is derived and shown to conceal pitfalls while using Redlich–Kister coefficients to estimate partial Molar properties of the components. The zero-powered terms, which are the same for the alternative expansions, are shown to yield four-fold the excess Molar Property for the equiMolar mixture. Literature data for the partial Molar volume of water at infinite dilution in 15 neat aminoalkanols at different temperatures are collected and tabulated. These data generally show a positive dependence of that limiting value on the temperature, the only apparent exception being in the case of 1-aminopropan-2-ol. It is demonstrated that the recently published data for this aminoalkanol [S. Mokraoui, A. Valtz, C. Coquelet, D. Richon, Thermochim. Acta 440 (2006) 122–128] were ill-treated and recalculated limiting values are given, which increase with increasing temperature.
Jaime D. Gomes De Oliveira - One of the best experts on this subject based on the ideXlab platform.
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The two faces of the Redlich–Kister equation and the limiting partial Molar volume of water in 1-aminopropan-2-ol
Thermochimica Acta, 2008Co-Authors: Jaime D. Gomes De Oliveira, Joao Carlos R ReisAbstract:Abstract The properties of the Redlich–Kister equation when expressed in power series of x1 − x2 are related to its alternative expression in terms of power series of x2 − x1, where x1 and x2 are mole fractions of the components 1 and 2 of a binary liquid mixture. The simple relationship between both sets of coefficients is derived and shown to conceal pitfalls while using Redlich–Kister coefficients to estimate partial Molar properties of the components. The zero-powered terms, which are the same for the alternative expansions, are shown to yield four-fold the excess Molar Property for the equiMolar mixture. Literature data for the partial Molar volume of water at infinite dilution in 15 neat aminoalkanols at different temperatures are collected and tabulated. These data generally show a positive dependence of that limiting value on the temperature, the only apparent exception being in the case of 1-aminopropan-2-ol. It is demonstrated that the recently published data for this aminoalkanol [S. Mokraoui, A. Valtz, C. Coquelet, D. Richon, Thermochim. Acta 440 (2006) 122–128] were ill-treated and recalculated limiting values are given, which increase with increasing temperature.
Jaime Gomes D De Oliveira - One of the best experts on this subject based on the ideXlab platform.
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the two faces of the redlich kister equation and the limiting partial Molar volume of water in 1 aminopropan 2 ol
Thermochimica Acta, 2008Co-Authors: Jaime Gomes D De Oliveira, Joao Carlos R ReisAbstract:Abstract The properties of the Redlich–Kister equation when expressed in power series of x1 − x2 are related to its alternative expression in terms of power series of x2 − x1, where x1 and x2 are mole fractions of the components 1 and 2 of a binary liquid mixture. The simple relationship between both sets of coefficients is derived and shown to conceal pitfalls while using Redlich–Kister coefficients to estimate partial Molar properties of the components. The zero-powered terms, which are the same for the alternative expansions, are shown to yield four-fold the excess Molar Property for the equiMolar mixture. Literature data for the partial Molar volume of water at infinite dilution in 15 neat aminoalkanols at different temperatures are collected and tabulated. These data generally show a positive dependence of that limiting value on the temperature, the only apparent exception being in the case of 1-aminopropan-2-ol. It is demonstrated that the recently published data for this aminoalkanol [S. Mokraoui, A. Valtz, C. Coquelet, D. Richon, Thermochim. Acta 440 (2006) 122–128] were ill-treated and recalculated limiting values are given, which increase with increasing temperature.
Jacob G. Reynolds - One of the best experts on this subject based on the ideXlab platform.
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The Component Slope Linear Model for Calculating Intensive Partial Molar Properties: Application to Waste Glasses and Aluminate Solutions - 13099
2013Co-Authors: Jacob G. ReynoldsAbstract:Partial Molar properties are the changes occurring when the fraction of one component is varied while the fractions of all other component mole fractions change proportionally. They have many practical and theoretical applications in chemical thermodynamics. Partial Molar properties of chemical mixtures are difficult to measure because the component mole fractions must sum to one, so a change in fraction of one component must be offset with a change in one or more other components. Given that more than one component fraction is changing at a time, it is difficult to assign a change in measured response to a change in a single component. In this study, the Component Slope Linear Model (CSLM), a model previously published in the statistics literature, is shown to have coefficients that correspond to the intensive partial Molar properties. If a measured Property is plotted against the mole fraction of a component while keeping the proportions of all other components constant, the slope at any given point on a graph of this curve is the partial Molar Property for that constituent. Actually plotting this graph has been used to determine partial Molar properties for many years. The CSLM directly includes this slope in a model that predicts properties as a function of the component mole fractions. This model is demonstrated by applying it to the constant pressure heat capacity data from the NaOHNaAl(OH)4-H2O system, a system that simplifies Hanford nuclear waste. The partial Molar properties of H2O, NaOH, and NaAl(OH)4 are determined. The equivalence of the CSLM and the graphical method is verified by comparing results determined by the two methods. The CSLM model has been previously used to predict the liquidus temperature of spinel crystals precipitated from Hanford waste glass. Those model coefficients are re-interpreted here as the partial Molar spinel liquidus temperature of the glass components.
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The Component Slope Linear Model for Calculating Intensive Partial Molar Properties: Application to Waste Glasses
2013Co-Authors: Jacob G. ReynoldsAbstract:Partial Molar properties are the changes occurring when the fraction of one component is varied while the fractions of all other component mole fractions change proportionally. They have many practical and theoretical applications in chemical thermodynamics. Partial Molar properties of chemical mixtures are difficult to measure because the component mole fractions must sum to one, so a change in fraction of one component must be offset with a change in one or more other components. Given that more than one component fraction is changing at a time, it is difficult to assign a change in measured response to a change in a single component. In this study, the Component Slope Linear Model (CSLM), a model previously published in the statistics literature, is shown to have coefficients that correspond to the intensive partial Molar properties. If a measured Property is plotted against the mole fraction of a component while keeping the proportions of all other components constant, the slope at any given point on a graph of this curve is the partial Molar Property for that constituent. Actually plotting this graph has been used to determine partial Molar properties for many years. The CSLM directly includes this slope in a model that predicts properties as a function of the component mole fractions. This model is demonstrated by applying it to the constant pressure heat capacity data from the NaOH-NaAl(OH{sub 4}H{sub 2}O system, a system that simplifies Hanford nuclear waste. The partial Molar properties of H{sub 2}O, NaOH, and NaAl(OH){sub 4} are determined. The equivalence of the CSLM and the graphical method is verified by comparing results detennined by the two methods. The CSLM model has been previously used to predict the liquidus temperature of spinel crystals precipitated from Hanford waste glass. Those model coefficients are re-interpreted here as the partial Molar spinel liquidus temperature of the glass components.
R. De Lisi - One of the best experts on this subject based on the ideXlab platform.
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Thermodynamics of Solubilization of Pentanol in Sodium Dodecyl Sulfate-Dodecyldimethylamine Oxide Mixed Micelles
Journal of Colloid and Interface Science, 1994Co-Authors: Stefana Milioto, R. Crisantino, R. De LisiAbstract:Abstract Heat capacity and density measurements of pentanol (PeOH)-sodium dodecyl sulfate (NaDS)-dodecyldimethylamine oxide-water mixtures were carried out at 0.03 m PeOH as a function of the total surfactants concentration (mc) at different ratios (XNaDS). From experimental data, the apparent Molar volumes (VΦ,R) and heat capacities (CΦ,R) of PeOH in the surfactants mixture solutions were calculated. As a general feature, at a given mixture composition, VΦ,R increases monotonically with mt as observed in pure surfactants. In the cases of XNaDS = 0.1 and 0.3, VΦ,R drops at about 0.1 and 0.15 mt respectively. The decreasing CΦ,R VS mt curve shows peculiarities which were ascribed to the presence of a liquid crystalline phase for XNaDS = 0.1 and 0.3 and of a structural micellar transition for XNaDs = 0.6 and 0.9. At a given XNaDS, the dependence of the apparent Molar Property of PeOH on mt was rationalized in terms of the distribution constant of alcohol between the aqueous and the micellar phases (K) and its partial Molar Property in the aqueous and the micellar phases. The standard free energy, calculated from the K values, and the partial Molar properties of PeOH in the surfactant-surfactant micelles change linearly with XNaDS according to the ideal behavior.