Unformatted text preview: only one independent variable. 810 | Thermodynamics
T, P NH3 + H2O VAPOR gf,NH3 = gg,NH3 gf,H2O = gg,H2O LIQUID NH3 + H2O (PH 1) has two independent variables. In other words, two independent intensive properties need to be specified to fix the equilibrium state of a pure substance in a single phase. Phase Equilibrium for a Multicomponent System
Many multiphase systems encountered in practice involve two or more components. A multicomponent multiphase system at a specified temperature and pressure is in phase equilibrium when there is no driving force between the different phases of each component. Thus, for phase equilibrium, the specific Gibbs function of each component must be the same in all phases (Fig. 1620). That is,
gf,1 gf,2 gf,N gg,1 gg,2 gg,N gs,1 gs,2 gs,N for component 1 for component 2 for component N FIGURE 1620 A multicomponent multiphase system is in phase equilibrium when the specific Gibbs function of each component is the same in all phases. pppppp 94 T, K 90 VAPOR 90.2 86
LIQ UI D A +V PO R 82 78 77.3 74 LIQUID 0 10 20 30 40 50 60 70 80 9...
View Full Document