Section //. Effect of Concentration on Conductance. 51 



Table 11. Values of the exponent n in the function C(A A) =K(C A). 



This form of function seems to us to furnish the best means of deter- 

 mining the value of A , at any rate in cases where a series of accurate 

 measurements at very small concentrations is not available ; we have 

 therefore employed this method generally throughout this series of inves- 

 tigations. The values of A given in table 9 (except those at 18 which 

 were derived by Kohlrausch and Maltby) were obtained in this way by 

 graphic extrapolation upon the plots just referred to. 



It is interesting to compare the A values to which this method leads 

 with those derived by Kohlrausch and his co-workers at 18 by appli- 

 cation of the function A A == KC h to his own conductivity-values at 

 very small concentrations (0.1 to 2 milli-normal). We have made the 

 necessary calculations for seven salts of two different types with the 

 following results. The table also contains the results obtained by Kohl- 

 rausch by applying the function A A = KOhP at concentrations 

 between 0.1 and 100 milli-normal. 



The values of A obtained from the conductances at moderate con- 

 centrations either by the Storch function or the Kohlrausch function 

 A A =KC l A? are seen to be usually somewhat higher than those derived 

 from the conductances at very low concentrations ; but the differences 

 are not as a rule very important, being less than 1 per cent, except in the 

 last two cases. 



*Assuming n l= 0.42 for KCl and NaCl, 0.50 for KNO3, 0.52 for AgN0 3 , 0.55 

 for Ba(N0 3 )2, 0.45 for K2SO4, and 0.40 for CaCl 2 , which are the values which give 

 a most nearly linear function between 2 and 50 milli-normal. With K 2 SOi, however, 

 no value of the exponent gave a fully satisfactory expression of the conductance 

 values. Incidentally it is of interest to note that the conductance value at 100 

 milli-normal was greater than that required by the assumed function by the following 

 percentage amounts: 0.36 for KCl, 0.00 for NaCl, 0.06 for AgNOs, 0.00 for 

 Ba(N0 3 ) : , 0.4 for K-SO*, and 0.3 for CaCk 



