188 



CONDUCTIVITY AND VISCOSITY IN MIXED SOLVENTS. 



Tables 81 and 82 (figs. 88 and 89) show that potassium sulphocyanate, in 

 mixtures of ethyl alcohol and water, exhibits a minimum in conductivity 

 at 0, in the 50 and 75 per cent mixtures, in all cases except the N/10 solu- 

 tion, and at 25 the minimum is shown only in the N/800 and N/1600 

 solutions, in the 75 per cent mixture. The curves which do not show actual 

 minima, exhibit a decided drop below the average values for the two sol- 

 vents. They also show that there is only a very slight increase in conduc- 

 tivity with increase in dilution in the mixed solvents, and particularly in the 

 25 per cent and 50 per cent mixtures. It is to be noted, however, that the 

 increase in conductivity with increase in dilution is greater in ethyl alcohol 



no-J 



100- 



oo- 



80- 



3 

 

 d 



6 



d 



3 

 53 



70- 



50H 



40- 



30- 



20- 



2554 5054 7556 



Percentage of Methyl AlcohoL 



FIG. 91. CONDUCTIVITY OF POTASSIUM SULPHOCYANATE IN MIXTURES 

 OF METHYL ALCOHOL AND ETHYL ALCOHOL AT 25. 



than it is in water for this particular salt. It is also to be noted that the actual 

 value for conductivity in water is much greater than it is in ethyl alcohol. 

 The temperature coefficients of conductivity show an increase with increase in 

 the dilution of the solution, in every case, and these values are greatest in the 

 50 per cent mixture. 



Tables 81 and 82 (figs. 90 and 91) show that potassium sulphocyanate, in 

 mixtures of methyl alcohol and ethyl alcohol, does not exhibit a minimum in 

 conductivity, but nevertheless there is an appreciable dropping of the curves, 

 plotted from these values, below the average value. It is to be noted also 

 that the increase in conductivity with increase in dilution is practically the 

 average increase as calculated from the increase in the pure solvents. It is 



