CONCENTRATED AQUEOUS SOLUTIONS, AND HYDRATION OF THE SOLUTE. 865 



Fig. 4, p. 864, shows the general character of the curves for which values of 

 /Uy/yM^ at 9 9 "4° are plotted against gramme equivalents per litre. These show that 

 the ratio of concentration to Mv/^a, varies very considerably for different salts even to 

 the highest concentrations. The difference in these values are in general less divergent 

 the higher the concentration. In fig. 5 values of Mv/V^ at 0° and at 99 '4° Centigrade 

 have been plotted against concentration. The 0° point curves have been marked with 

 zeros, the 99 "4° Centigrade curves with 99 '4. On comparison, it is seen that the zero 

 curves, speaking generally, lie more to the right of the diagram than the 99 '4° curves, 



Aiv/A-o 



Av/M°<> 



Fig. 5. 



Fig. 6. 



which indicates a greater degree of ionization at the lower than at the higher tempera- 

 ture. It is evident that the zero curves are at the higher concentrations inclined at a 

 smaller angle to the axis of Mv/V^, and that consequently the curves for the two 

 temperatures approach each other at the high concentrations, and may even cross each 

 other. In fig. 6, the relations between curves at 99*4° Centigrade and at other 

 temperatures are shown. From these it appears that for the dilute solutions the 

 ionization is greater for the lower temperature at the same concentration, but that for 

 the concentrated solutions the ionization, or rather the value of /* V //* M , is greater at the 

 higher temperature. It would seem also that, the nearer the temperature of the 

 observations for the isothermals for which the comparison is made, the lower is the 

 concentration at which their point of intersection lies. 



