SOLUBILITIES OF ARGON, OXYGEN AND NITROGEN IN 1,2-PROPANEDIOLPLUSWATER MIXED-SOLVENT AT 298.15-K AND 101.33-KPA

Solubilities of argon, oxygen and nitrogen were determined in 1,2-prop anediol+water mixed solvent over the full range of composition by a st atic method. Gas solubility measurements were carried out at a tempera ture of 298.15 K and pressure of 10133 kPa. Both the excess quantity r eferring to the Ostwald coefficient and to the excess volume of solven t mixture showed similar relation having minima against the volume fra ction composition of 1,2-propanediol. The order of gas solubility expr essed by the Ostwald coefficient in 1,2-propanediol+water mixed solven t was argon > oxygen > nitrogen in full range of composition. Furtherm ore, the excess Ostwald coefficients on the basis of volume fraction w hich express the non-ideality of gas solubility in non-ideal solutions were defined, and excess Ostwald coefficient of these three solute ga ses in 1.2-propanediol+water mixed solvent showed one parabolic curve against volume fraction of 1,2-propanediol. This result means that exc ess Ostwald coefficients of these gases do not depend on the type of s olute gas, but on solvent. This property was similar to that of monoal cohol aqueous solutions.