OF VITAL PHENOMENA 



55 



solutions is more than is expected. The anomaly may be ex- 

 plained by the hypothesis that the hydration of ions is less in the 

 concentrated solution, they move faster and increase the con- 

 ductivity, and, hence, the high dissociation is only apparent 

 (G. N. Lewis). The dissociation of concentrated solutions of 

 HC1 as calculated from electrode potential (J. Ellis, 1916) is 

 much greater than that calculated from conductivity data. The 

 two curves for dilute solutions are shown in Fig. 21. 



'.In HCl 



Fig. 21. Curves showing the difference between the dissociation of HCl 

 as measured by electric conductivity (conductance ratio) and electrode 

 potential (hydrogen ion concentration). 



In a molecular solution of an acid v = 1 and the formula 

 a 2 H'XA' 



becomes : c = 



HA 



-, where H' and A' represent 



