Aqueous solutions of gases

Table 12.1. Partial pressures and concentrations of aqueous solutions of gases at 303 K...

Natural water is an aqueous solution of gases, ions and molecules, but it also contains undissolved, suspended and/or colloidal inorganic particles of different size and chemical composition and biogenic living and/or dead matter such as cells, plants, and animals etc., sometimes termed hydrosol. Water occurs in the climate system in different forms ... 

Some general comments regarding the application of the SPT to water are now in order. First, the SPT was originally devised for treating a fluid of hard spheres or simple non-polar fluids. The extension of the theory to complex fluids such as water is questionable. Second, the SPT employs an effective diameter of the solvent as the only molecular parameter. It is very likely that this diameter is temperature dependent. It is not clear, however, which kind of temperature dependence should be assumed for aitj. [This topic was discussed by Ben-Naim and Friedman (1967) and Pierotti (1967).] Finally, we stress again that the SPT is not a pure molecular theory. Even if it can predict the properties of aqueous solutions of gases, it is still incapable of providing an explanation of these properties. This is an inherent drawback of the theory since it cannot tell us why aqueous solutions behave in such a peculiar way as compared with other fluids. 

Water in most practical applications may be considered to be a dilute aqueous solution of gases and salts. 

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