Dilute solution in which the solute may be regarded as obeying
Henry's law, so that all the solute
activity coefficients may be approximated to 1.
Source:
Physical Chemistry Division, unpublished
See also:
PAC, 1994, 66, 533
(Standard quantities in chemical thermodynamics. Fugacities, activities and equilibrium
constants for pure and mixed phases (IUPAC Recommendations 1994))
on page 545