WORK OF J. N. PEARCE. 



63 



The values of H are plotted in the curve (fig. 22) against the concentration as 

 abscissas. An explanation regarding these hydrate curves is necessary at this point. 

 With one or two exceptions, it was found impossible to plot on the paper the values 

 of H for the more dilute solutions. 



These curves show the rapid decrease in hydration until the minimum is reached, 

 and then a very slight decrease with increasing concentration. 



Table 45. Calcium Chloride Data for Freezing-point and Conductivity Measurements, 



Specific Gravity, and Hydrates. 



STRONTIUM CHLORIDE. 



The concentrated mother-solution was diluted to convenient strength and equal 

 portions were taken for standardization. The strontium was precipitated and 

 weighed as strontium carbonate. 



The conductivity measurements for this salt gave, at maximum dissociation, 

 /zoo = 128.57. The corresponding value obtained by Jones and Stine was /xoo = 128.44. 



The minimum in the freezing-point lowerings (column L') is found at 0.25 normal, 

 whereas the minimum in the total combined water occurs at a somewhat greater 

 dilution (0.05 normal). The values of H become approximately constant at 0.25 

 normal, the minimum point in the freezing-point lowering. 



The values of m and H for calcium and strontium chlorides, tables 45 and 46, 

 show numbers of approximately the same order of magnitude. For curves, see 

 figs. 22 and 23. 



As in the case of calcium chloride, the values of the theoretical lowerings (L) are 

 less than the observed lowerings (Z/) in every instance. 



