Calculation of Fugacity (Solids)

Fugacities of solids are calculated using the Poynting method, with the exception that the volume in the Poynting correction is the volume of the solid phase.

 Poynting method for solids.

Any of the methods for vapors may be used for calculation of ϕ^sat. P^sat is obtained from thermodynamic tables. Equations of state are generally not applicable for calculation of solid phases because they are used only to represent liquid and vapor phases. However, they may be used to calculate the fugacity of a vapor phase in equilibrium with a solid, given by ϕ^satP^sat. As for liquids, the Poynting correction may be frequently set to unity with negligible error.