28 



WORK OF C. M. STINE. 



For the sake of comparison, the values oi' M for calcium chloride and magnesium 

 chloride in separate solutions are plotted as curves against concentration (as axis of 

 abscissas). Upon the same sheet are drawn similar curves for the values of M in 

 the mixture. 



Table 14. Hydration in the Mixture of Calcium Chloride and Magnesium Chloride. 



m 



m c 



a 



M 



Sp. gr. 

 cor. 



M c 



H e 



1.3CaCl 2 0.65 



1.3MgCl 2 0.65 



1.7CaCU 0.85 



1.7MgCl 2 0.85 



2.1 CaCl 2 1.05 



2.1MgCl 2 1.05 



2.5CaCl 2 1.25 



2.5MgCl 2 1.25 



2.9CaCl 2 i 1.45 



2.9MgCl 2 i 1.45 



0.454 

 0.460 

 0.406 

 0.396 

 0.357 

 0.336 

 0.314 

 0.278 

 0.275 

 0.220 



3.548 

 3.570 

 3.371 

 3.332 

 3.187 

 3.264 

 3.028 

 2.895 

 2.883 

 2.479 



15.74) 

 17.79/ 

 18.921 

 21.73/ 

 21.921 

 25.06/ 

 24.32) 

 28.14/ 

 27.29) 

 30.86/ 



9.32 



13.5 



19.5 



27.25 



37.0 



3.0 

 4.0 

 5.2 

 6.5 

 7.8 



fl4.5 

 116.4 

 fl7.1 

 ,19.6 

 [19.8 

 122.7 

 [22.8 

 126.3 

 [25.9 

 128.9 



22.3 

 25.2 

 20.1 

 23.1 

 18.9 

 21.6 

 18.2 

 21.0 

 17.9 

 19.9 



Upon comparing curve I, fig. 3, the hydra- 

 tion of magnesium chloride alone, with curve 

 IV, the hydration of the calcium chloride in 

 the mixture, it will be seen that where I rises 

 IV falls, and vice versa. This is exactly what 

 we should expect, since an increase in the 

 hydrating power of magnesium chloride should 

 result in a corresponding decrease in the 

 amount of water with which the calcium chlo- 

 ride would be able to combine in the mixture, 

 unless a corresponding increase in the hydrat- 

 ing power of the calcium chloride in separate 

 solution should also occur. Again, comparing 

 curves I and II, and III and IV, the hydrates 

 in separate solution and in the mixture are of 

 the same general order of magnitude, except 

 where the presence of the one salt in the mix- 

 ture alters the composition of the hydrate 

 formed by the other. 



It was thought desirable to compare the effect of 

 a salt with less hydrating power mixed with one of 

 greater hydrating power. 



For this purpose calcium chloride and stron- 

 tium chloride were selected, the hydrating power 

 of strontium chloride being somewhat less than 

 that of calcium chloride. 



The data for the separate solutions of calcium chloride have already been given 

 Those of strontium chloride follow in tables 15 and 16. 



4) 



C 



E 







i. 



3 

 u 



o 

 2 







o 



o 



V 



S 



3 



O 



H 



.5 1. 1.5 



Gram Molecules of Salt 

 per Liter of Solution 

 Fig. 3. 



I. Magnesium Chloride Alone. 

 II. Magnesium Chloride Mixed with Calcium 

 Chloride. 

 III. Calcium Chloride Alone. 

 IV. Calcium Chloride Mixed with Magnesium 

 Chloride. 



