activity coefficient, f,γ

https://dx.doi.org/10.1351/goldbook.A00116
The activity coefficientf B of a substance B in a liquid or solid mixture containing mole fractions x B,x C, ... of the substances B, C, ... is a dimensionless quantity defined in terms of the chemical potentialμ B of B in the mixture by:
R T ln ( x B f B ) = μ B cd T P x − μ B * cd T p
where x denotes the set of mole fractions x B,x C, ... . The activity coefficientγ B of a solute B in a solution (especially a dilute liquid solution) containing molalities m B,m C, ... of solutes B, C, ... in a solvent A is a dimensionless quantity defined in terms of the chemical potentialμ B by:
R T ln ( m B γ B m ⊖ ) = μ B − μ B − R T ln ( m B m ⊖ ) ∞
Source:
PAC, 1994, 66, 533 (Standard quantities in chemical thermodynamics. Fugacities, activities and equilibrium constants for pure and mixed phases (IUPAC Recommendations 1994)) on page 543
PAC, 1994, 66, 533 (Standard quantities in chemical thermodynamics. Fugacities, activities and equilibrium constants for pure and mixed phases (IUPAC Recommendations 1994)) on page 546
PAC, 1990, 62, 2167 (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2171
PAC, 1996, 68, 957 (Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)) on page 960