For a given component, the excess of this quantity is RT times the log of its activity coefficient, and its residual is RT times the log of its fugacity coefficient.
This quantity can be calculated -3kT times the natural log of an insertion parameter over the thermal de Broglie wavelength. For a given component, the excess of this quantity is RT times the log of its activity coefficient, and its residual is RT times the log of its fugacity coefficient. For an electron, this quantity is the negative electronegativity. At constant temperature and pressure, the sum of mole fraction times this quantity for each component equals zero, according to the most common version of the Gibbs-Duhem equation. It's not concentration, but neutral mass diffusion always occurs along gradients of this quantity. Like fugacity, for two phases in equilibrium, this quantity is the same for each component. For 10 points, name this quantity, the partial molar Gibbs free energy, symbolized mu.
This quantity can be calculated -3kT times the natural log of an insertion parameter over the thermal de Broglie wavelength.
chemical potential [or partial molar Gibbs free energy before it is read; prompt on just "Gibbs free energy"]