"Hydrotropic solutions are aqueous salt solutions which effect increased solubility of substances insoluble or slightly soluble in water at the same temperature. It is a salting-in effect as compared with the more commonly known salting-out effect. Relatively concentrated salt solutions are required to effect a marked change in solubility of the third component. In general, the third component is reprecipitated by diluting with two to three volumes of water. The solvent may then be made ready for re-use by reconcentration by evaporation."
This thesis is a kinetic study of the vapor phase addition of hydrogen chloride to propylene using activated alumina es a catalyst. Preliminary work on this reaction showed first, that isopropyl chloride is the only gaseous product formed at temperatures of 80°C or less when this catalyst is used. Second, the catalyst activity decreases with time possibly due to the formation of non-volatile polymerized product on the surface. The rate of decreasing catalyst activity is dependent on the temperature and on the conversion.