148 



CONDUCTIVITY AND VISCOSITY IN MIXED SOLVENTS. 



In the pure ethyl alcohol the temperature coefficients increase with the 

 dilution. They are largest, for the most part, in the 50 per cent mixture. 



Tables 71 and 72 (figs. 66 and 67) make it clear that in a mixture of 

 methyl and ethyl alcohols the conductivity of cobalt chloride exhibits no 

 minimum value. There is a sagging of the curves, which demonstrates 

 that the values obtained are less than what we should expect from the law 

 of averages. 



Tables 71 and 72 (figs. 68 and 69), for cobalt chloride in mixtures of acetone 

 and water, show a point of inflection at low temperatures and high dilution. 

 Attention should be called to the fact that the conductivity values in pure 

 acetone at 25 are less than the corresponding values at 0, thus giving negative 

 temperature coefficients. The values in pure acetone for /u, v are small at both 

 temperatures and at all dilutions. 



Percentage of Methyl Alcohol 



FIG. 66. CONDUCTIVITY OF COBALT CHLORIDE IN MIXTURES 

 OF METHYL ALCOHOL AND ETHYL ALCOHOL AT 0. 



From a study of tables 71 and 72 (figs. 70 and 71) we see that cobalt 

 chloride, in mixtures of acetone and methyl alcohol, gives neither a minimum 

 nor a maximum in conductivity. The values at most of the dilutions are 

 what we should expect from the law of averages. It should be recalled that 

 lithium bromide, in mixtures of acetone and methyl alcohol, gives a maximum 

 in conductivity at both temperatures. 



