[[Vapor-Liquid Equilibrium of Mixtures]] ### For one component ![[lever rule.jpg|lg]] V<sub>T</sub> = x<sub>L</sub>V<sub>L</sub> + x<sub>v</sub>V<sub>v</sub> ![[lever rule volume.jpg]] [[Internal Energy (U) of a system is its total energy content|U]]<sub>T</sub> = U<sub>L</sub>x<sub>L</sub> + U<sub>v</sub>x<sub>v</sub> [[Enthalpy (H) is the heat energy of a system|H]]<sub>T</sub> = H<sub>L</sub>x<sub>L</sub> + H<sub>v</sub>x<sub>v</sub> Use the lever rule to calculate mole fraction, specific volumes of liquid and vapor in a saturated solution For steam, get the individual properties from [[Steam Properties|steam tables]] ### For a mixture [[Thermodynamic properties of mixtures]] ![[000 Publish/attachments/lever rule mixtures.jpg]] The liquid ($L$) and vapor ($V$) fractions of a mixture can easily be calculated from one component’s mole fraction overall ($z_1$) and in the liquid ($x_1$) and vapor ($y_1$) phases: $L = \frac{y-z}{y-x} \qquad V= \frac{z-x}{y-x}$ ![[lever rule mixtures 2.jpg]] This is derived from the combination of mole balances for individual components and mole balances for vapor/liquid phase. ![[lever rule mass balances.jpg]]