SOLUTIONS AS A FUNCTION OF TEMPERATURE 175 



dielectric constant are completely ionized, then it becomes exceedingly 

 difficult to account, on the one hand, for the very low value of the con- 

 ductance of these solutions at certain intermediate and low concentra- 

 tions and, on the other hand, for the very rapid increase in the conduct- 

 ance of these solutions at higher concentrations. So, in the case of 

 solutions in the neighborhood of the critical point, it is difficult to account 

 for the rapid decrease in the conductance of the solution as the critical 

 point is approached on the basis of this hypothesis. Again, in the case 

 of solutions above the critical point, the large increase in the conductance 

 of the solution as the concentration of the solvent increases is with diffi- 

 culty accounted for on the assumption that the electrolyte is completely 

 ionized, unless, at the same time, an hypothesis is introduced according 

 to which the speed of the ions through the solvent medium is enormously 

 increased by an increase in the concentration of the solvent. For such 

 an hypothesis there is an entire lack both of experimental facts and of 

 theoretical support. 



On the other hand, if the fundamental elements of the usual theory 

 of electrolytes are accepted, we are forced to the conclusion that the ion- 

 ization of electrolytes is a complex function of the concentration and that, 

 at very high concentrations, in the case of solvents of low dielectric con- 

 stant, the ionization increases with the concentration. While theoretical 

 support is lacking for this assumption, no theoretical principle's are con- 

 tradicted by such an hypothesis. Furthermore, if we assume that the 

 ionization of electrolytes is a function of the concentration and is approxi- 

 mately measured by the conductance ratio -T-, the influence of tempera- 



A 



ture, of concentration, and of the viscosity of the solvent may be readily 

 accounted for without contradicting known facts and without intro- 

 ducing any further hypotheses for which a theoretical foundation is 

 lacking. In other words, on the basis of the ionization hypothesis, it is 

 necessary to make only a single assumption whose correctness remains 

 uncertain, whereas in the case of other hypotheses a number of assump- 

 tions are necessary. Unless other and more conclusive facts can be 

 adduced in support of the hypothesis that the strong electrolytes are 

 completely ionized in solution, this hypothesis is clearly untenable at 

 the present time. 



