# Fugacity of component i in Vapor phase

Not Reviewed
hatf_i^V =
DavidC.Fugacity of component i in Vapor phase
The fugacity coefficient hatvarphi_i, for component i in the vapor is calculated from an equation of state (e.g., Virial). Sometimes it is approximated by a pure component value from a correlation.  The fugacity coefficient is a correction for vapor phase non-ideality.  Often at pressures close to atmospheric, hatvarphi_i= 1