104 



HYDRATES IN AQUEOUS SOLUTION. 



ACETONE. 



The freezing-point lowerings produced by acetone increase considerably 

 with increase in the concentration of the solution, but the correction for 

 specific gravity is unusually large (table 84). When the proper corrections 

 are applied, the "true molecular lowerings" decrease with increase in the 

 concentration of the solutions. The experimental values at all concentra- 

 tions studied are below the calculated value for a non-dissociated, non- 

 polymerized substance, and at great concentrations the values found fall 

 very much below the theoretical value (column L', table 84). 



This shows that the acetone undergoes polymerization in such solutions, 

 the amount of the polymerization being a function of the concentration 

 increasing from the most dilute to the most concentrated solutions studied. 

 The freezing-point curve is plotted in fig. 59. 



TABLE 84. ACETONE. 



ACETAMIDE. 



While the value of for acetamide increases rapidly with the concentra- 



m 



tion, the corrected molecular lowering in table 85 does not change appre- 

 ciably in magnitude. Indeed, the values found at the various dilutions 

 do not vary greatly from the theoretical value 1.86. This indicates that 

 acetamide neither forms hydrates nor undergoes polymerization at any 

 dilution. 



There is, of course, the possibility that these influences are simultaneously 

 operative, but, in order that this should be true, we would have to assume 

 that the magnitude of each of these influences was exactly equal at all con- 

 centrations, which is a highly improbable assumption. The freezing-point 

 data for acetamide are plotted in fig. 59. 



