CHEMICAL THEORY OF SOLUTIONS. PART T. 57 



or as §t ^ C'ß '' = Ck from equation (32) 





r l + (v-l)6^p Y 



As both Cy. and 0:i ai-e necessarily less than unity, . as well 

 as -/T-2' must be positive throughout. We see further from equa- 

 tion (32) that Cß approaches zero far more rapidly than Ca when 

 X approaches zero. Hence at x = 



mr^ (^°) 



apd -^ir is also zero. On the other hand at a: = 1 we have 



(4^1= "(C,) (41) 



\ dx /I 



where (Q)i denotes the molar fractton of ©ß in the associated 

 component in the pure state. From these considerations it is 

 clear that the curve showing the relation between x and C\i must 

 have a form like ß in Fig. 12. 



As to the curve representing the molar fraction of the 

 normal component as a function of x, we see from equation (35) 

 that it must throughout lie above the diagonal Bl (Fig. 12). 

 Its shape can be further elucidated from the following considera- 

 tions. From equation (30) we have 



dC dO^ dCo, 



dx dx dx ' 



