Solubility of solids in near-critical fluids IV. CHI3 and I2 in trifluoromethane

ERNESTO MARCECA; ROBERTO FERNÁNDEZ PRINI

JOURNAL OF CHEMICAL THERMODYNAMICS

Elsevier

Año: 1994 vol. 26 p. 651 - 661

0021-9614

The solubilities of I2(s) and CHI3(s) in near-critical fluid CHF3 have been determined with the high-pressure spectrophotometric technique and with the sampling and analytical procedure described previously. Isothermal-solubility measurements were carried out under subcritical conditions in the dense liquid phase at the temperature T = (293.62 ± 0.02) K for both solutes and under supercritical conditions at T = (303.80 ± 0.02) K for CHI3 and at T = (308.26 ± 0.01) K for both solutes; isobaric runs were done for the two solutes at a pressure of (8.008 ± 0.002) MPa. As expected, solubilities showed a strong dependence on p and T close to the thermodynamic state where the compressibility or thermal expansivity of the solvent passes, respectively, through a maximum. It is observed that I2 is almost ten times more soluble than CHI3 in near-critical CHF3. The results obtained in all the studies of this series are compared in terms of enhancement factors which eliminate the influence of the vapour pressure of the solid solute upon the observed solubility. A discussion of the observed qualitative features and their relation to molecular interactions is attempted.