348 PROPERTIES OF ELECTRICALLY CONDUCTING SYSTEMS 



polymerized molecules were capable of ionization, intermediate ions 

 would be present in solution and transference measurements with such 

 solutions, therefore, should yield very abnormal values for the transfer- 

 ence numbers. While certain transference numbers are unquestionably 

 abnormal and while it is indeed very probable that polymerization often 

 occurs in solutions of electrolytes in solvents of both high and low dielec- 

 tric constant, it remains to be shown that the phenomenon is a general 

 one and that it is capable of accounting for the observed properties of 

 electrolytic solutions. Nevertheless, it is highly probable that the effect 

 of polymerization will have to be taken into account in many cases at 

 higher concentrations. It appears, however, that polymerization should 

 lead to a lower rather than to a higher value of the conductance. Trans- 

 ference measurements with the alkali metal halides in acetone yield 

 abnormally high values for the cations, indicating the formation of a 

 complex cation. It is to be noted, however, that the conductance of the 

 halide is the lower the greater its tendency to form complexes. Thus, the 

 conductance of lithium chloride in acetone at higher concentrations is 

 much lower than that of potassium iodide or sodium iodide. That com- 

 plex ions are formed in solutions of cadmium iodide in water was shown 

 by Hittorf, as has already been pointed out. The assumed ionization 

 process in solutions of electrolytes is in a large measure hypothetical. 

 This may account for numerous discrepancies at higher concentrations. 



Other writers consider solutions of strong electrolytes to be similar 

 to solutions of colloids. Among these are Reychler, 32 Georgievics 33 and 

 Wo. Ostwald. 34 These theories, however, appear to be little more than 

 analogous, based chiefly upon the similarity between the Storch equation 

 and the adsorption equation. The Storch equation is only an approxima- 

 tion in aqueous solutions which, in other solvents, fails entirely. The 

 osmotic effects in solutions of electrolytes, also, are not in harmony with 

 the view that solutions of strong electrolytes are colloidal in character. 



Some writers attempt to account for the properties of aqueous solu- 

 tions by taking into account reactions between the solvent and the elec- 

 trolyte. In this connection, it is to be noted that electrolytic solutions are 

 not confined to solvents of the water type. Indeed, such solvents need 

 not necessarily contain hydrogen and, in fact, may be elementary sub- 

 stances, or neutral carbon compounds such as chloroform. In view of 

 this fact, it is highly improbable that the properties of electrolytic solu- 

 tions may be generally accounted for on the basis of chemical processes 



82 Reychler, "Etude sur 1'Equilibre de Dissociation," Brochure No. 3, Bruxelles (1917), 



83 Georgievics, Ztschr. f. pJiys. Chem. 90, 356 (1915). 

 "Ostwald, Ztschr. Ctiem. Ind. Roll. 9, 189 (1911). 



