46 AKT. 10. — K. IKEDA : STUDIES ON THE 



In the table the result of calculation is compared with the 

 observation of A. E. Taylor (Journ. physic. Chem., 4, 336 ; 

 1900). The agreement is quite satisfactory. The degree of 

 association ç has been calculated by equation (26). 



The heat of evaporation for one mol of vapour at the boiling 

 point 56.2° has been calculated to be 



1 — 6' 



_^ £i+q^ = 7520 calories. 



s 



[q^ is set 10.9x311.71x1.985 = 6744 calories]. The calculation 

 according to the well known equation, 



Molecular heat of evaporation = '' ^ ' — ^ — ^ — —, 



from Taylor's data gives 7640 calories, while Wirtz (Landolt- 

 Börnstein-Meyerhofer's Tabellen) has determined it to 7300 ca- 

 lories. Were acetone a normal liquid the molecular heat of 

 evaporation would amount to only 6960 calories. 



(c) Acetaldehydc and Paraldehyde. 



The equilibrium between acetaldehydc and paraldehyde has 

 been studied by Hollmann (Zeits. physik. Chem., 43, 129; 1903) 

 under the guidance of R00ZEB0031. The peculiarity of the system 

 is that the reaction 



3 Co H, O ;l Co Hio O, 



proceeds so very slowly at lower temperatures, that the chemical 

 species can be treated as independent components, while at higher 

 temperatures or in the presence of catalysers the reaction takes 

 place so rapidly that the state of equilibrium is reached in a 



