150 HYDRATES IN AQUEOUS SOLUTION. 



tration of the solution, which we see from the results takes place in the case 

 of all three of the above salts. The dissociation would decrease with increase 

 in the concentration, which would tend to diminish the magnitude of the 

 molecular rise of the boiling-point as the solutions became more and more 

 concentrated. 



Attention should also be called to the magnitude of the molecular rise in 

 the most concentrated solutions employed. In such solutions it is almost 

 twice the boiling-point constant, or normal molecular rise for this solvent. 

 The dissociation in such solutions is certainly not greater than between 30 

 and 40 per cent. 



We should interpret these results in terms of the same theory that was 

 advanced by Jones* in connection with aqueous solutions. There is combi- 

 nation between the solvent and the dissolved substance, forming in the case 

 of water, hydrates; in the case of alcohol, alcoholates in solution. As the 

 concentration of the solution becomes greater, more and more alcohol is 

 held in combination by the dissolved substance; consequently, there is less 

 and less alcohol acting as solvent, and the molecular rise in the boiling-point 

 therefore increases. 



RESULTS WITH ETHYL ALCOHOL. 



The results in ethyl alcohol, obtained with lithium chloride, lithium bro- 

 mide, lithium nitrate, and calcium nitrate, are given in table 100 (page 151). 



Jones and McMaster obtained results of the same general character as those 

 found by Jones and Getman for the substances with which they worked in 

 ethyl alcohol. The constant for ethyl alcohol is 1.15. If we examine the 

 results for lithium chloride, bromide, and nitrate, we shall find the molecular 

 rise in the boiling-point, especially in the more concentrated solutions, to be 

 much greater than this value. Further, the molecular rise increases with the 

 concentration of the solutions. The results in the more dilute solutions in 

 ethyl alcohol might be partially explained on the basis of dissociation, since 

 ethyl alcohol -has about one-fourth the dissociation power of water. Disso- 

 ciation, however, is incapable of explaining the magnitude of the molecular 

 rise in the more concentrated solutions, and is entirely incapable of explain- 

 ing the fact that the molecular rise of the boiling-point increases with the 

 concentration of the solution up to the most concentrated solutions that 

 were employed. 



Calcium nitrate is an exception to the above relations, as was found earlier 

 by Jones and Getman. f As this was rather surprising, Jones and McMaster 

 repeated the work, and obtained essentially their results. The molecular rise 

 in the boiling-point of ethyl alcohol produced by calcium nitrate decreases 

 from the most concentrated solution studied, with a fair degree of regularity. 

 In the most concentrated solutions, the molecular rise becomes less than the 



*Amer. Chem. Journ., 23, 103 (1900). } Ibid., 32, 338 (1904). 



