chemical potential, \(\mu _{\text{B}}\)

https://doi.org/10.1351/goldbook.C01032
The chemical potential of a substance B in a mixture of substances B, C ... is related to the Gibbs energy G of the mixture by: \[\mu _{\text{B}}=(\frac{\partial G}{\partial n_{\text{B}}})_{T,p,n_{\text{C}\neq \text{B}}}\] where T is the thermodynamic temperature, p is the pressure and n B, n C, ... are the amounts of substance of B, C, ... . For a pure substance B, the chemical potential µ B * is given by: \[\mu _{\text{B}}^{*}=\frac{G^{*}}{n_{\text{B}}}=G_{\text{m}}^{*}\] where Gm* is the molar Gibbs energy, and where the superscript * attached to a symbol denotes the property of the pure substance. The superscript Θ or ° attached to a symbol may be used to denote a standard thermodynamic quantity.
See also: standard chemical potential
Sources:
Green Book, 2nd ed., p. 49 (https://dev.goldbook.iupac.org/files/pdf/green_book_2ed.pdf)
PAC, 1994, 66, 533. 'Standard quantities in chemical thermodynamics. Fugacities, activities and equilibrium constants for pure and mixed phases (IUPAC Recommendations 1994)' on page 535 (https://doi.org/10.1351/pac199466030533)
PAC, 1996, 68, 957. 'Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)' on page 966 (https://doi.org/10.1351/pac199668040957)