chemical potential, μB

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:

$μ B = ( ∂ G ∂ n B ) T , p , n C ≠ B$

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:

$μ B * = G * n B = G m *$

where $G m *$ is the molar Gibbs energy, and where the superscript * attached to a symbol denotes the property of the pure substance. The superscript $⊖$ or $o$ attached to a symbol may be used to denote a standard thermodynamic quantity.