FORM OF THE CONDUCTANCE FUNCTION 



85 



stants assumed are: D = 1.703, K = 0.001, and A = 129.9 for all curves, 

 while ra = 0.52 for Curve I,m = 1.50 for Curve II, and ra = 1 f or Curve 

 III. The greater the value of ra, the less rapidly does K' increase at the 

 lower concentrations. For a value of m = 0, the curve degenerates into 

 a horizontal straight line, corresponding to the mass-action constant 

 K' = K + D. 



.8 



1.6 



1.4 



1.2 



0.4 



0.1 



CUPVlfy 



/fa*t 



0.1 



0.2 0.3 0.4 0.5 0.6 



Ion Concentration (Cy). 



0.7 0.8 09 



FIG. 13. Showing Typical K' Curves for Different Values of m According to 



Equation 11. 



It is evident that a given percentage deviation of K' with respect to 

 K will be found at different values of the ion concentration. If we con- 

 sider two solutions for which the value of K' has increased by a given 

 percentage amount over K in both cases, then the ion concentrations of 

 the two solutions are related according to the equation: 



(34) 



K 



If D/K for the two solutions is of the same order, then the ratio of 

 the ion concentrations will depend upon the values of ra. The smaller 

 the value of ra, the lower will be the ion concentration at which a given 

 change in K will be found. This is also obvious from Figure 13. For 



