Volatile electrolytes, solubility

Clegg, S.L. and Brimblecombe, R (1990) Solubility of volatile electrolytes in multi-component solutions with atmospheric applications. In Chemical Modelling in Aqueous Systems II (eds Melchior, D.C. and Bassett, R.L.). American Chemical Society, Washington, DC. 

Soluble substances fall into two classes those that give solutions which do not conduct electricity, called non-electrolytes and those that give solutions that do conduct electricity, called electrolytes. In solution non-electrolytes behave normally, or in other words, molecular weight methods show the same number of moles that one would expect to find in the gaseous state of that substance if it were volatile. Electrolytes, on the other hand, show a greater number of moles than one would normally expect to find. 

Solubility of Volatile Electrolytes in Multicomponent Solutions with Atmospheric... 

Fluorocarbons are made commercially also by the electrolysis of hydrocarbons in anhydrous hydrogen fluoride (Simons process) (14). Nickel anodes and nickel or steel cathodes are used. Special porous anodes improve the yields. This method is limited to starting materials that are appreciably soluble in hydrogen fluoride, and is most useflil for manufacturing perfluoroalkyl carboxyflc and sulfonic acids, and tertiary amines. For volatile materials with tittle solubility in hydrofluoric acid, a complementary method that uses porous carbon anodes and HF 2KF electrolyte (Phillips process) is useflil (14). 

Now interpret phase X as pure solute then Cs and co become the equilibrium solubilities of the solute in solvents S and 0, respectively, and we can apply Eq. (8-58). Again the concentrations should be in the dilute range, but nonideality is not a great problem for nonelectrolytes. For volatile solutes vapor pressure measurements are suitable for this type of determination, and for electrolytes electrode potentials can be used. 

Ionic liquid solvents are non-volatile and non-toxic and are liquids at ambient temperature. Originally, work was concerned with battery electrolytes. These ionic liquids (IL) show excellent extraction capabilities and allow catalysts to be used in a biphasic system for convenient recycling (Holbrey and Seddon, 1999). IFP France has commercialized a dimerization process for butenes using (LNiCH2R ) (AlCU) (where L is PRj) as an IL and here the products of the reaction are not soluble in IL and hence separate out. The catalyst is very active and gives high selectivity for the dimers. 

In the case of molten salts, the functional electrolytes are generally oxides or halides. As examples of the use of oxides, mention may be made of the electrowinning processes for aluminum, tantalum, molybdenum, tungsten, and some of the rare earth metals. The appropriate oxides, dissolved in halide melts, act as the sources of the respective metals intended to be deposited cathodically. Halides are used as functional electrolytes for almost all other metals. In principle, all halides can be used, but in practice only fluorides and chlorides are used. Bromides and iodides are thermally unstable and are relatively expensive. Fluorides are ideally suited because of their stability and low volatility, their drawbacks pertain to the difficulty in obtaining them in forms free from oxygenated ions, and to their poor solubility in water. It is a truism that aqueous solubility makes the post-electrolysis separation of the electrodeposit from the electrolyte easy because the electrolyte can be leached away. The drawback associated with fluorides due to their poor solubility can, to a large extent, be overcome by using double fluorides instead of simple fluorides. Chlorides are widely used in electrodeposition because they are readily available in a pure form and... 

Gtickel, W., Kastel, R., Lawerenz, J., Synnatschke, G. (1982) A method for determining the volatility of active ingredients used in plant protection. Part III The temperature relationship between vapour pressure and evaporation rate. Pestic. Sci. 13,161-168. Hafkenscheid, T. L., Tomlinson, E. (1981) Estimation of aqueous solubilities of organic non-electrolytes using liquid chromatographic retention data. J. Chromatogr. 218, 409 -25. 

On the Solubility of Volatile Weak Electrolytes in Aqueous Solutions... 

Maurer G. On the solubility of volatile weak electrolytes in aqueous solutions. ACS Symp Ser 1980 133 139-172. 

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