Solubility of xenon in liquid n-alkanols: Thermodynamic functions in simple polar liquids

Abstract

Measurements of the Ostwald solubility L(T) as a function of temperature in the range 10.0–50.0 °C are reported for 133Xe gas in 13 liquid normal alcohols: methanol through n-dodecanol, and n-tetradecanol. From the data for each solute–solvent system we find the mole fraction solubility x2(T), and calculate the following thermodynamic functions of solution: chemical potential Δμ○2(T) =−RT ln x2, enthalpy ΔH̄○2, and entropy ΔS̄○2, all based on the mole fraction scale. We also calculate directly from the Ostwald solubility the corresponding quantities based on the number density scale. These quantities are the chemical potential Δμ○ρ2(T) =−RT ln L, enthalpy ΔH○ρ2, and entropy ΔS○ρ2. The solute was chosen as an inert monatomic gas and the solvents were chosen in a polar homologous series in order to construct prototype solute–solvent systems. Solubility results and the associated thermodynamic functions are analyzed and compared with simple models.

Some remarks on the solubility of gases in liquid long-chainn-alkanes andn-alkan-1-ols

“…In addition to our results, a few supplementary literature data on Xe solubilities [7][8][9] have been included. Of particular note is the (several Xe solubilities) [9].…”

“…In addition to our results, a few supplementary literature data on Xe solubilities [7][8][9] have been included. Of particular note is the (several Xe solubilities) [9]. The broken curves are only meant to indicate the general trends existence of maxima at small values of l for some gas/n-alkan-l-ol series (/_<4), in contradistinction to what is observed in the gas/n-alkane series, where in all cases L2,1 decreases monotonously with increasing l. These maxima become more prominent, the larger the solute and/or the solubility of the solute.…”

NMR chemical shifts of129Xe dissolved in various oxygen and nitrogen substituted straight chain aliphatic compounds

“…A pressure of 11.2 atm was used in the case of water in order to offset the extremely low solubility exhibited by Xe in water. Literature values are available for the solubility of Xe in ethylene glycol [8], water [9] and the long chain alcohols used here [10]. A comparison of these data reveals that the maximum Xe solubility expected for these solvents will be that encountered with Xe in undecanol at 3.7 atm.…”

“…A comparison of these data reveals that the maximum Xe solubility expected for these solvents will be that encountered with Xe in undecanol at 3.7 atm. The one atm mole fraction solubility of Xe in undecanol is measured to be: X = 0.0198 at 20~ [10], leading one to expect that the mole fraction solubility of Xe will be approximately X = 0.07 in this solvent at 3.7 atm. This is lower than the Xe concentration encountered earlier with n-alkanes under the same conditions [7] and leads one to conclude that Xe-Xe interactions will not contribute significantly to the chemical shifts recorded in these experiments.…”

Enthalpy of solvation correlations for organic solutes and gases dissolved in 1-propanol and tetrahydrofuran

“…Calorimetric data was also found for the dissolution of a few gases in tetrahydrofuran [141,142], and for five crystalline organic solutes, ethylene carbonate [143], benzamide [144], benzoic acid [145], 1-bromoadamantane [146] and 1-adamantanol [147], in 1-propanol. Enthalpies of solution of several gas molecules [148][149][150][151][152][153][154][155],…”