112 



HYDROGEN ION CONCENTRATION 



A is here the molar conductivity of the electrolyte at the concentra- 

 tion c (i.e., the specific conductivity at concentration c, divided by c) 

 and A 00 is the limiting value of this molar conductivity for infinite 

 dilution. For such infinite dilution the dissociation may be assumed 

 to be complete, or a = 1. If this rule be applied to a weak electrolyte 

 a value of k is obtained which is independent of the concentration, 

 as has been shown a very great number of times, and as it is illustrated 

 for acetic acid, as an example, in table 18. 



TABLE 18 



TABLE 19 



* Aoo 

 t Aoo 

 J Am 



380.5. 

 238.6. 



78.5. 



Should we now attempt to apply the same method to KCl we 

 should find that the value for k obtained will not be constant, but 

 will vary in a definite direction. It will definitely increase with the 

 concentrations of the salt. The same is true for all strong electro- 

 lytes such as HCl, HBr, HI, NaOH, KOH, as well as for all salts, 

 and even for such salts as ammonium acetate. Definite indications 

 of this relationship are already evinced by the strongest of the weaker 

 electrolytes, such as picric acid, tartaric acid, etc. Table 19 illus- 



