74 PROPERTIES OF ELECTRICALLY CONDUCTING SYSTEMS 



entirely independent of each other, or, in other words, they depend in 

 a corresponding manner upon some property of the electrolyte. The 

 values of ra lie between 0.70 and 1.18 and, for the most part, they lie 

 between 0.82 and 0.96. The general form of the curve, as we shall 

 presently see, is determined largely by the value of the constant ra. It 

 follows, consequently, that the curves for the various electrolytes will in 

 general be similar. No definite relation appears to exist between the 

 values of the constant ra and the constants D and K. In many cases, 

 however, as we shall see later, electrolytes having a small value of K 

 and D have a relatively large value of ra. Silver iodide is an exception 

 to this rule. 



The constants for a number of organic electrolytes are given in 

 Table XXVIII. 



TABLE XXVIII. 



CONSTANTS OF EQUATION 11 FOR ORGANIC ELECTROLYTES 

 IN NH 3 AT 33. 



Solute Ao 10 4 # ra D 



Cyanacetamide 260 0.045 1.24 0.026 



Benzenesulphonamide 208 1.39 1.00 0.029 



Methylnitramine 256 8.4 0.85 0.080 



Metanitrobenzenesulphonamide 231 12.5 0.76 0.103 



Nitrourethaneammonium 262 21.6 0.76 0.22 



Trinitraniline 234 30.0 0.73 0.38 



They have been arranged in the order of increasing values of K. It is 

 at once evident that there is no relation between the various constants 

 and the value of A . On the other hand, there is apparently a rough 

 parallelism between the constants K and D. The order of the K and D 

 constants, in other words, is identical. The order of the constant ra 

 appears to be the reverse of that of the constants D and K; that is, as 

 K and D increase, ra decreases. 



Aside from solutions in liquid ammonia, the equation has been found 

 to hold for solutions in sulphur dioxide, 7 amyl and propyl 8 alcohols and 

 phenol. 9 In the case of the sulphur dioxide solutions the equation holds 

 within the limits of experimental error. In that of the alcohol solu- 

 tions, the deviations appear to be considerable at certain points, but it is 

 possible that these are due either to experimental errors or to a lack of 

 proper adjustment of the constants. The constants found are as follows: 



7 Kraus and Bray, loc. cit. 



Keyes and Winninghoff, J. Am. Chem. Soc. 38, 1178 (1916). 



Kurtz, Thesis, Clark University (1921). 



