The solubility of argon in aqueous solutions of a complex-ion electrolyte

From measurements of the solubility of argon in aqueous solutions of the complexion electrolyte t-[Co(en)₂NCSCl]Br at 25°C, the Setschenow parameter for this system is found to be +0.33₆. Using the scaled-particle theory of the salt effect with this value ofk₅ and the Waddington crystal radius of the Br^– ion, 1.98 Å, the radius of the complex cation is calculated to be 3.71 Å. This value is in reasonably good agreement with that estimated from scale models of the t-[Co(en)₂-NCSCl]⁺ cation, about 3.9 Å. It is somewhat larger than the radius calculated from various semiempirical equations relating the molal volume of an ion at infinite dilution to its radius; values of r obtained in this manner range from 3.32 to 3.66 Å.Abstracted, in part, from D.P.'s M.S. thesis, June 1971.