Effect of temperature and pressure on Henrys law constants

Consider the solution process B(g) B(soln) for a nonelectrolyte solute B. The expression for the thermodynamic equilibrium constant, with a solute standard state based on mole fraction, is 

These expressions can be used with little error at any pressure that is not much greater than p°, say up to at least 2 bar, because under these conditions Fx,b does not differ appreciably from unity (page 274). 

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