Solubility of gases in water at various temperatures

In the preceding table are given the solubilities of a few typical gases in water at various temperatures. Unless otherwise stated the solubility co-efficient j8 is employed. j3l signifies measurement of the gaseous volume at N.T.P., but the pressure includes the vapour pressure of the liquid also, whereas jS signifies the volume under the pressure of the gas itself of 760 mm. (see p. 36). 

Recent applications of the theory have been made for calculating the contribution the formation of a cavity gives to the free energy of transfer of a series of isomeric ketones(134), or various other solutes(132), from H2O to D2O, for the studies of solubility of many apolar gases in water and other polar solvents(135), for comparing the experimental thermodynamic data for the solution of rare gases(51), or some perfluorocarbon gases(136), in water at various temperatures with data calculated by means of the SPT. In a tentative made to extend the theory at aqueous solutions where solute-solute interactions have to be considered and hydrophobic interactions are operative, it has been shown that the dependence of the partial molar volumes and enthalpies of hard-sphere solutes in water on concentration and temperature are due to the anomalous trends the 63/6P and 63/6T (3 coefficient of isothermal compressibility) of pure water present, rather than to the solute structural effects(137). 

Table 21.22 Saturated solubilities of atmospheric gases in sea-water at various temperatures Concentrations of oxygen, nitrogen and carbon dioxide in equilibrium with 1 atm (lOI 325 N m ) of designated gas...

The presence of the radioactive gas radon (Rn) in well water obtained from aquifers that lie in rock deposits presents a possible health hazard in parts of the United States, (a) Assuming that the solubility of radon in water with 1 atm pressure of the gas over the water at 30 °C is 7.27 X 10 M, what is the Henry s law constant for radon in water at this temperature (b) A sample consisting of various gases contains 3.5 X 10 mole fiaction of radon. This gas at a total pressure of 32 atm is shaken wdth water at 30 °C. Calculate the molar concentration of radon in the water. 

This paper is a critical review of the low-pressure solubility of 57 gases In liquid water and in heavy water. The solubility of each gas is given in terms of the coefficients of an equation which can be used to calculate the solubility at a given temperature. Also given are aG", AH , AS , and AC° values for the solution process at various temperatures and at one atmosphere partial pressure of the gas. The authors give extensive details concerning their correlations and include references to the literature. 

The solubilities of the various gases in [BMIM][PFg] suggests that this IL should be an excellent candidate for a wide variety of industrially important gas separations. There is also the possibility of performing higher-temperature gas separations, thanks to the high thermal stability of the ILs. For supported liquid membranes this would require the use of ceramic or metallic membranes rather than polymeric ones. Both water vapor and CO2 should be removed easily from natural gas since the ratios of Henry s law constants at 25 °C are -9950 and 32, respectively. It should be possible to scrub CO2 from stack gases composed of N2 and O2. Since we know of no measurements of H2S, SO, or NO solubility in [BMIM][PFg], we do not loiow if it would be possible to remove these contaminants as well. Nonetheless, there appears to be ample opportunity for use of ILs for gas separations on the basis of the widely varying gas solubilities measured thus far. 

Gas-liquid relationships, in the geochemical sense, should be considered liquid-solid-gas interactions in the subsurface. The subsurface gas phase is composed of a mixture of gases with various properties, usually found in the free pore spaces of the solid phase. Processes involved in the gas-liquid and gas-solid interface interactions are controlled by factors such as vapor pressure-volatilization, adsorption, solubility, pressure, and temperature. The solubility of a pure gas in a closed system containing water reaches an equilibrium concentration at a constant pressure and temperature. A gas-liquid equilibrium may be described by a partition coefficient, relative volatilization and Henry s law. 

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