OF CERTAIN SALTS IN TERNARY MIXTURES. 



135 



These curves show that the same relation is true for the ternary sol- 

 vents. Sufficiently dilute solutions have not been used in this work 

 to determine the dissociation accurately, no measurements beyond 

 N/800 having been made. The data obtained by Jones and Bingham, 

 and the work on glycerol-water and acetone-water mixtures indicate 

 that solutions more dilute than N/1600 must be used. Decrease in 

 dissociation from 15 to 35 is slight, and is not sufficient to explain 

 the difference between the fluidity and conductivity coefficients. 

 Rubidium and ammonium salts are not in the class of salts that form 

 complex solvates, yet of the known factors which affect conductivity 

 the formation of solvates is the only one which can explain the point 

 here raised. If a solvate is formed and the rise in temperature reduces 

 its complexity less than it increases the fluidity of the solvent, the 

 above is a satisfactory explanation. In this connection it should be 

 noted that Jones and Guy 1 have found some evidence for the formation 



60 



40 



30 



20 



10 



V=2 



V=4 



V=4 



V = 10 

 V=2 



2-1-1 2-2-1 2-1-2 1-1-1 1-2-1 1-1-2 1-2-2 Solvents 



FIG. 54. Fluidity of ammonium iodide in glycerol, acetone, and water, at 25. 



of glycerolates by sodium and potassium salts. The acetone-water 

 investigation shows some evidence for the formation of solvates by 

 rubidium salts in a mixed solvent. Another factor which should be 

 investigated is the polymerizing action of acetone and the effect of 

 temperature on the complexity of the polymers. 



It should be noted that figures 55 and 56 show two distinct types 

 of curves. In figure 55 both conductivity and fluidity curves are 

 regular, while in figure 56 both curves show a minimum. The mini- 

 mum occurs at the N/4 point. The effect on conductivity of the usual 

 increase in dissociation from N/2 to N/4 is overcome by the decrease 

 in fluidity, thus producing the minimum point. From N/4 to N/10 

 there is little change in fluidity, hence the increase in dissociation gives 

 the curves a sharp upward turn. In figure 55 the influence of increas- 

 ing fluidity and dissociation work together, producing a convex curve. 



Carnegie Inst. Wash. Pub. No. 180. 



