Solubility of solids in near-critical fluids III. CHI3 and CI4 in sulphur hexafluoride
✍ Scribed by Ernesto Marceca; Roberto Fernández-Prini
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 277 KB
- Volume
- 25
- Category
- Article
- ISSN
- 0021-9614
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✦ Synopsis
The solubilities of (\mathrm{CHI}{3}(\mathrm{~s})) and (\mathrm{Cl}{4}(\mathrm{~s})) in near-critical fluid (\mathrm{SF}{6}) have been spectrophotometrically determined. Due to the low solubilities of the two solids in (\mathrm{SF}{6}), a new sampling and analytical procedure had to be developed to enable their measurement in the low solvent-density region, because they were below the detection limit of the previously developed spectrophotometric method. Isothernal solubility measurements were carried out under subcritical conditions in the dense liquid phase at temperature ((302.20 \pm 0.01) \mathrm{K}) for (\mathrm{CHI}{3}) and ((303.57 \pm 0.04) \mathrm{K}) for (\mathrm{CI}{4}), and under supercritical conditions at ((322.76 \pm 0.03) \mathrm{K}) for (\mathrm{CHI}{3}) and ((322.92 \pm 0.02) \mathrm{K}) for (\mathrm{Cl}{4}); two isobaric runs were done for (\mathrm{CHI}{3}) at pressures of ((3.818 \pm 0.003) \mathrm{MPa}) and ((4.478 \pm 0.001) \mathrm{MPa}). Solubilities depend strongly on (p) and (T) close to the thermodynamic state where the compressibility or thermal expansivity of the solvent pass, respectively, through a maximum. It is observed that (\mathrm{CI}{4}) is almost ten times less soluble than (\mathrm{CHI}{3}) in near-critical (\mathrm{SF}{6}). Moreover, the solubilities in (\mathrm{SF}_{6}) are about ten times lower than in ethene.
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