i 3 8 



THEORY OF CONCENTRATED SOLUTIONS. 



hence addition of either excess A or excess B lowers the active 

 mass of the compound. Hence the concentration or active mass 

 of the compound ought to be a maximum when the solution has 

 the same percentage composition as the compound itself. 



It has been shown that this result is obtained easily from 

 the law of mass action if active mass be taken as equivalent to 

 molar fraction. It is not thus obtainable if active mass be 



Percentage of alcohol by wtight. 

 Fig. 2. 



expressed as mols per unit volume, because in the ap])ropriate 

 mass law expression 



(y — x){i — y — nx)" = Kl'".\ 

 there are three variables x, y, and I '. 



I have, however, already shownf that in a binary mixture 

 where chemical combination occurs between the components, the 



* For the representation of active mass by molar fraction see also 

 G. N. Lewis: /. Amer. Chetn. See, 1908, and Dolezalek : Zeit. Physik. 

 Clionic, 1908. 



t Faraday Pec. Trans 1012. 



