Activity of a Solute from Distribution between Two Immiscible Solvents

3 ACTIVITY OF A SOLUTE FROM DISTRIBUTION BETWEEN TWO IMMISCIBLE SOLVENTS 

If the solute in solution A is in equUibrium with that in solution B, its escaping tendency is the same in both solvents. Consequently, its chemical potential p,2 at equihbiium also must be identical in both solvents. Nevertheless, the solute will have different activities in solution A and B since [Equation (16.1)] 

Therefore, to calculate (o2)b from (fl2)A. we must find the difference between the chemical potentials in the respective standard states. From Equation (15.10) 

To determine the ratio of the activities in the two solvents, then, we need to determine the ratio of the Henry s-law constants for the solute in the two solutions. 

At equilibrium, (/2)a = (/2)b. because both solutions are in equilibrium with the same vapor, and 

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