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Physical Constants of Organic Compounds
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
2-Ethylstyrene 3-Ethylstyrene 4-Ethylstyrene Ethyl sulfate 2-(Ethylsulfonyl)ethanol 2-Ethyl-5-(3-sulfophenyl)isoxazolium hydroxide, inner salt Ethyl tartrate 2-Ethyltetrahydrofuran 5-Ethyl-1,3,4-thiadiazol-2amine S-Ethyl thioacetate (Ethylthio)acetic acid (Ethylthio)benzene Ethyl thiocyanate
An improved correlation for thermophysical properties of binary liquid mixtures
Published in Chemical Engineering Communications, 2023
Gustavo A. Iglesias-Silva, José J. Cano-Gómez, Mariana Ramos-Estrada, Kenneth R. Hall
The Redlich-Kister (R-K) equation can correlate the thermophysical properties as where JE is the thermophysical property; x1 and x2 are the molar fractions of components 1 and 2; and are temperature-dependent adjustment parameters. It is obvious that in some cases, such as the molar heat capacity, it requires only two terms because the molar heat capacity is a straight line. With two terms, the Redlich-Kister equation cannot correlate this “W”-shape. Usually, it requires up to 4 terms. Belda (2009b) already has shown that with two parameters Equation (4) is slightly better than the Redlich-Kister equation. Equation (16) has only three adjusting parameters (or four if the exponent is adjusted) and Equation (17) has four adjusting parameters, but they rarely are necessary. Marsh (1977) has proven that rational forms are superior functions to correlate the excess enthalpy and Gibbs energies. Equation (19) can become a Redlich-Kister type equation when m2 = 0. With three statistically valid parameters, the Redlich-Kister equation correlates as well as Equation (17). However, if Equation (17) has the same number of statistically valid parameters, the Redlich-Kister equation is only better for 4 cases. In some cases, the prediction of the Redlich-Kister equation for excess properties is not correct. Figure 14 shows these cases for the mixtures of methanol (1) + 1-ethyl-3-methylimidazolium ethyl sulfate (2), and ethanol (1) + n-heptane (2) at 298.15 K and 293.15 K, respectively.