BCHLUNDT DIELECTRIC CONSTANTS OF PURE SOLVENTS. 



385 



that ferric chloride does not yield conducting solutions with 

 ethylene chloride [D. C. = 11.3 1 ], but it yields solutions with 

 several other solvents having dielectric constants of about the 

 same order or even less, which have very distinct conductivity. 

 Here, then, we have a number of additional exceptions to the 

 Nernst-Thomson rule. 



The exceptions to the Nernst-Thomson rule noted above in 

 connection with liquid ammonia solutions, however, do not indi- 

 cate the general behavior of ammonia solutions of the common 

 salts. While it is true that ammonia solutions for the most 

 part show greater molecular conductivity than aqueous solu- 

 tions of the same concentration, yet the degree of dissociation is 

 as a rule less than that of the corresponding aqueous solutions. 

 This point is well illustrated by the following table taken from 

 the work of Franklin and Kraus. 2 It shows the dilution at 

 which dissociation reaches 90$ in the two solvents. 



Table XI. 



Carrara's scheme for comparing the dissociating power by cal- 

 culating the dilution for the same solute in which a definite de- 

 gree of dissociation is obtained by electrical conductivity meas- 

 urements, seems an excellent one to apply in this connection to 

 solvents which yield good conducting solutions. In the follow- 

 ing table the volumes of the solvents enumerated correspond to 



i Jahn and Moller: Zeit. phys. Chem. 13, 335, (1894), 

 3 Am. Chem. Jour. 23, 297, (1900). 



