CHEMICAL THEORY OF SOLUTIONS. PART I. 





.(3) 



where /h, /^2, »Te the molecular chemical potentials, z^, z.z, 



the molecular thermodynamic potentials in the isolated 



state, and C[, CI, the molar fractions (the thermodynamic 



or numerical concentrations) of the components ©i, S2, 



The relation expressed by (3) can be readily deduced from (1) 

 and (2). From the latter we see that the work gained by mixing 

 must be i)roportional to absolute temperature, and from (1) that it is 

 independent of pressure. When the temperature is sufficiently raised 

 and the pressure sufficiently lowered the mixture as well as the com- 

 ponents is in a state approaching that of ideal gases and the work 

 obtainable by reversible mixing of the components is equal to 



- nJtTln C\ - ÏU RT In C\- 



which is proportional to the absolute temperature. The work obtain- 

 able by the formation of the solution can therefore be represented by 

 the same expression. Z, the thermodynamic potential (or the available 

 energy at constant temperature and pressure) of the solution must be 

 equal to the sum of the available energies of the components minus 

 the work obtainable during the formation of the solution. Hence 



Z = i\z^ + n^. + + ?ii liTln C^ + n^ BT In C.+ , 



which on differentiation with respect to Wj, n.^, gives: 



A = 4^ = z, + HTlnC\ 



"^^ = z.+nThia 



Ö??o 



In the foregoing deductions it is not necessary to make any assump- 

 tion as to tlie molecular weights of the components in the liquid state. 



