150 HYDROGEN ION CONCENTRATION 



according to Ostwald's dilution law, or, according to the mass law, 



c = k 



1 - a 



where k is the dissociation constant of the electrolyte. By letting 

 a = 0.5 we obtain 



0.25 



c = k 



0.5 



or 



c = 2 k 



therefore, c is proportional to k. 



By substituting k for c in the above equation 



Di : Ds = 'V'^ : \'^U 



where ki and k2 are the dissociation constants of the electrolytes 

 in the two solvents. Then Walden also found that actually this 

 relation was fairly valid for a large series of electrolytes. But the 

 electrolytes tested by him were exclusively of the strong type (such 

 as KCl, Nal, AgNOg, N(C2H5)4l, etc.) to which Ostwald's dilution 

 law cannot be apphed. Thus there are still difficulties in the way 

 of estabhshing Walden's theory. 



Certain further elucidation concerning the dissociation of electro- 

 lytes in organic solvents is found in the investigations of R. Beutner 

 (I.e.): 



Many of the inorganic electrolytes, such as KCl, very soluble in 

 water, are not at all measurably soluble in oils.® A much better 

 insight can be had by working with organic acids and bases and 

 with their salts. Thus, if salicylic acid is dissolved in nitrobenzene, 

 the conductivity increases perceptibly; hkewise with dimethyl- 

 toluidine. Now, if equivalent amounts of salicylic acid and dimethyl- 

 toluidine be dissolved in the same solvent, the resulting conductivity 

 is appreciably greater than the sum of the individual conductivities. 

 We may conclude from this that the salt is more strongly dissociated 

 than the acid or the base, as is always the case in aqueous solutions. 



^ The author uses the term "oil," in this connection and in subsequent 

 chapters, to designate any oily liquid, generally forming a separate phase 

 when in contact with an aqueous phase. — Translator. 



