Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

This work is inserted in a research program that consists mainly in the experimental and theoretical study of the effect of association between solute and solvent molecules in the solubility of gases in liquids. The solubilities of hydrofluorocarbons, HFCs, (CH3F, CH2F2, CHF3) in lower alcohols (methanol, ethanol, 1-propanol, 1-butanol) have been determined in the temperature range [284-313] K, at atmospheric pressure. An automated apparatus based on Ben-Naim Baer and Tominaga et al. designs was used, which provides an accuracy of 0.6 %. A precision of the same order of magnitude was achieved. To represent the temperature dependence of the mole fraction solubilities, the equation R ln(x2) = A + B/T + C ln(T) was used. From this equation, the experimental Gibbs energies, enthalpies and entropies of solution at 298 K and 1 atm partial pressure of the gas, were calculated. A semiempirical correlation has been developed between the solubilities of HFCs in alcohols at 298K and the Gutmann acceptor number of solvents, AN, and reduced dipole moment of the gases.