Wikipedia - Diskussion:Massenwirkungsgesetz fugacity $$f$$, $$\tilde{p}$$

https://doi.org/10.1351/goldbook.F02543
Of a substance B, $$f_{\text{B}}$$ or $$\tilde{p}_{\text{B}}$$, in a gaseous mixture is defined by $$f_{\text{B}}=\lambda _{\text{B}}\ \lim _{p\rightarrow 0}\frac{p_{\text{B}}}{\lambda _{\text{B}}}$$, where $$p_{\text{B}}$$ is the @P04420@ of B and $$λ_{\text{B}}$$ its @A00019@.
Source:
Green Book, 2nd ed., p. 50 [Terms] [Book]
See also:
PAC, 1984, 56, 567. (Physicochemical quantities and units in clinical chemistry with special emphasis on activities and activity coefficients (Recommendations 1983)) [Terms] [Paper]
PAC, 1994, 66, 533. (Standard quantities in chemical thermodynamics. Fugacities, activities and equilibrium constants for pure and mixed phases (IUPAC Recommendations 1994)) [Terms] [Paper]