OF CERTAIN SALTS IN TERNARY MIXTURES. 131 



DISCUSSION OF RESULTS. 



As in , our preceding work with rubidium and ammonium salts in 

 glycerol and acetone and their binary mixtures with water, parallel 

 investigations in viscosity and conductivity have been carried out. 



We have obtained measurements with both concentrated and moder- 

 ately dilute solutions over a wide range of ternary mixtures of the three 

 solvents employed. Although glycerol and acetone of themselves are 

 immiscible, the addition of about 20 per cent water gives a perfectly 

 homogeneous liquid which corresponds to our 2-2-1 solvent. However, 

 it should be noted that in this solvent which contains the lowest per- 

 centage of water in the series, it was impossible to obtain concentrated 

 solutions of the ammonium salts while the rubidium salts failed to go 

 into solution at concentrations above 1/200 N., since the acetone 

 immediately separated out giving a non-homogeneous solution. 



As previously noted, table 33 shows the specific data relating to the 

 various mixtures, viz, the density, specific conductivity, viscosity, and 

 fluidity at all three temperatures studied. Reference to it will show 

 that, e. g., at 25, the standard comparison temperature, the solvents 

 possess densities ranging from 0.9984 for the 1-2-2 mixture to 1.0998 

 for the 2-1-1, while the viscosities for the same solvents vary between 

 0.02530 and 0.09706. Thus, the viscosities for the two extremes in 

 the series lie between those of 25 and 50 per cent glycerol and water 

 (0.02017-0.06021) for the former and between the 75 and 50 per cent 

 (0.0135 0.06021) for the latter extreme. The values, however, lie in 

 both cases nearest the least viscous glycerol mixture. 



The specific conductivity of the 1-1-1 solvent is about 3,000 times 

 that calculated by averaging the specific conductivities of each of the 

 constituents. Jones and Davis 1 have noted that in mixtures of glycerol 

 and water containing 50 and 25 per cent glycerol, the specific conduc- 

 tivity was higher than for pure water. Their explanation is that the 

 OH ion is split off; i. e., the glycerol is dissociated by the action of the 

 water. Jones and Bingham 2 have shown that the molecular conduc- 

 tivity of an N/200 solution of potassium iodide in acetone is about the 

 same as in pure water. As the fluidity of acetone is about 2^ times that 

 of water, the dissociating action of acetone would be of the order of 

 40 per cent that of water. The relative association factors of water 

 and acetone would lead to the same conclusion. While this conclusion 

 may not be quantitatively accurate, it is safe to say that acetone is a 

 strong dissociating agent. It is therefore possible that OH ions are 

 split off from the glycerol by the combined action of the water and 

 acetone, and possibly some from the water. This dissociation would 

 explain the very high specific conductivities of the solvents used in this 

 investigation as compared with those calculated by averaging the 

 specific conductivities of the constituents. 



'Carnegie Inst. Wash. Pub. No. 180. 2 Ibid., No. 80. 



