Determination of disG2 for Slightly Soluble Gases in Water using Solubility Data:

J. ALVAREZ AND R. FERNANDEZ-PRINI

JOURNAL OF SOLUTION CHEMISTRY

Springer Verlag

Lugar: Hamburgo; Año: 2008 vol. 33 p. 433 - 448

0095-9782

There is continuing interst in the description of the solubility of nonpolar gases in water over a wide tange of temperatures. On one hand, the solubility data are used in many fields of science and technology; and on the other hand, simulation and theoretical calculations require experimental data to test their results and predictions.  For these reasons it is importante to have a means of calculating from the xperimental solubility data the Gibbs enrgy of dissolution of gases and Henry's constant (kH) over all rthe temperature range of existence of liquid water.   Under ambient conditions it is relatively easy to relate these quantities with the solubility data on nonpolar gases. However, this simple procedure become3s increasingly complicated as the temperature approaches the critical temperature of the solvent and it si necessary to make important corrections to obtain the thermodynamic quantities for the dissolution process.  This difficulty can be resolved with a procedure that empoloyes a pertubation method applied to a simple model solvent to guide the correct determination of kH and Gibbvs enrgy.  We describe in this work an interative calculation procedure whose correctness was validated with a thermodynamic relationship that uses only experimental data, hence it is model fre.  Unfortunately this relationship can be applied only to a few systems due to its data requirements.  The iterative procedure described in this work can be xtended to higher pressures, up to 50 MPa, above the solvent's vapor pressure, and also to gases dissolved in nonaqueous solvents.