C. L. Speyers — Molecular Weights of Liquids. 433 



the vapor tension of the pure amylene at t°, p' the vapor ten- 

 sion of the amylene from the solution, n the per cent gram mo- 

 lecules of anilin in calculating which the normal molecular 

 weight of 93 is used, and a the activity factor computed accord- 

 ing to (3) using 70 as the molecular weight of amylene. Should 

 the vapor density of amylene be other than what corresponds 

 to 70, the value for a would have to be correspondingly changed. 



t=0° 



p = 180*6mmHg 



t = 



8-1° 



_p = 257 , 8minHg 



n 



p' 



a 



n 





P' 



a 



10-9 



168-9 



1-8 



10.9 





241-5 



1.8 



[15-0] 



164-8 



1-8 



[19-0] 





238-1 



2-8 



[77-5] 



u 



36 



[69-Oj 





cc 



27 



81-5 



162 



38 



75 





234 



29 



t = Ul 



o l) = 331-0mmHg 



t= 



18-1 



° p = 391nimHg 



n 



P 



a 



n 





P' 



a 



7-5 



315-0 



1-6 



24-2 





354-9 



3-1 



20 



308-3 



3-1 



35-1 





352-2 



4-9 



25-3 



303-0 



3-7 



49 





351 



8-4 



31*1 



303-2 



4-9 



69-9 





342-7 



16 



[37-0] 







73-1 





336*5 



17 



42-2 



301-8 



7-5 



82 





303-1 



16 



45-5 



302-0 



8-7 











50-7 



302-6 



11 



' t = \ 



25-1° 



_p=498-9mmHg 



[51-0] 







n 





P 



a 



59 8 



303-1 



16 



9.2 





476-6 



2-2 



65-3 



301-0 



19 



28-2 





458-9 



4-5 



75 



291-6 



22 



49*2 





453-8 



97 



80 



273-0 



19 



50-1 



59*8 

 66-7 



77-7 

 89-7 





453-1 



447-9 

 444-2 



411-8 

 295-4 



9-9 

 13 

 16 

 16 

 13 



From figure 1 we see that at 0° the two layers have the com- 

 position of 15'0 and 77*5 per cent grammolecules. These values 

 have been enclosed in [ ], Konowalow giving the vapor ten- 

 sion but not the corresponding compositions. Similarly for 

 the phases at 8*1°. Two phases should have formed at 14/1° 

 but they do not seem to have become visible. 



The values for a have been plotted in figure 2. The crosses 

 X mark the compositions of the coexistent phases. Plot 1 

 corresponds to 0°. We observe that in the phase dilute with 

 respect to anilin, the activity factor is small, only about 2, that 

 is, the anilin is comparatively active, but when the per cent of 

 anilin is large, the activity factor is very large up to about 36 

 so that now the anilin is very inert. At 0° then we may 

 expect to find dilate solutions of anilin in amylene more active 



