122 PROPERTIES OF ELECTRICALLY CONDUCTING SYSTEMS 



The significance of this result remains uncertain. It is to be expected, 

 however, that, on the addition of an electrolyte whose molecular weight 

 is lower than the mean of that of the solvent molecules, effects may occur 

 which cannot well be predicted on the basis of our present knowledge of 

 the viscosity relations in such mixtures. It is interesting to note that, 

 in the presence of non-electrolytes of high molecular weight, the coeffi- 

 cient for different electrolytes has very nearly the same value. Thus, 

 in the presence of raffinose the values of the exponent for lithium, potas- 

 sium and caesium chlorides are very nearly identical. Since these salts 

 have a common anion, it may be inferred that the influence of the vis- 

 cosity effect due to non-electrolytes of high molecular weight is the same 

 for the lithium, potassium and caesium ions. This is apparently not so 

 nearly true in the presence of non-electrolytes of low molecular weight, 

 but even here, in some instances at any rate, the exponent does not differ 

 greatly for different salts. It would seem that the influence of the vis- 

 cosity change on the .conductance of an ion, due to the electrolyte itself, 

 differs markedly from that due to the addition of a non-electrolyte. At 

 the present time, sufficient data are not available to enable us to draw 

 conclusions with any considerable degree of certainty. 



4. The Influence of Temperature on the Conductance of the Ions. 

 As is shown in Table XLII, with increasing temperature the conductance 

 of the ions increases, and this increase is the more nearly proportional 

 to the increase in the fluidity of the solvent, the lower the conducting 

 power of the ion. In the case of the acetate ion, the conductance is 

 everywhere proportional to the fluidity of water from to 156, which 

 is the entire interval over which the viscosity of the solvent has been 

 measured. In the following table are given the ratios of the fluidity of 

 water to the conductance of the acetate ion from to 156. 15 



TABLE XLIV. 



RATIO OP THE FLUIDITY OF WATER TO THE CONDUCTANCE OF THE ACETATE 

 ION AT DIFFERENT TEMPERATURES. 



Temp 18 25 50 75 100 128 156 



-T .... 2.73 2.72 2.73 2.72 2.71 2.72 2.71 2.71 



A CH 3 COCT 



It is evident that, in dilute solutions, the conductance of the acetate ion, 

 and presumably therefore its speed, is directly proportional to the fluidity 

 of the solvent. 



Since the conductance of the acetate ion is proportional to the fluidity 



" Johnston, loc. cit. 



