The corresponding value of y1 is found from Eq. At 750C, the saturated pressure is given by Antoine equation Substitute both values in (A) to find P y1 for a pressure of 70 kPaĪ) BUBL P calculations are required. Vapor pressure for the pure species are given by the following Antoine equations: i ii Raoult’s law equation can be solved for xi to solve for dewpoint calculation (T is given) 4 5Įxample 1 Binary system acetonitrile(1)/nitromethane(2) conforms closely to Raoult’s law. isomers such as ortho-, meta- & para-xylene) Assumptions ĭewpoint & Bubblepoint Calculations with Raoult’s Law FIND GIVEN BUBL P: Calculate and Pįor binary systems to solve for bubblepoint calculation (T is given) 2 3 Valid only if the species are chemically similar (size, same chemical nature e.g.Applicable for low to moderate pressure.10.1 – Shows the P-T-composition surfaces of equilibrium states of saturated V & saturated L of a binary system As pressure reduces, more & more L vaporizes until completed at W point where last drop of L (dew) disappear – dew point: a point when a vapor forms the first droplet of liquid and begins to condense Fig.Liquid at F, reduces pressure at constant T & composition along FG, the first bubble appear at L – bubble point: a point when a liquid forms the first bubble of vapor and begins to evaporate.contact to each other in a closed location.takes place when liquid and vapor are allowed to.e.g: mixture of liquid and vapor at an equilibrium.Binary mixture: Mixture that contains two constituents.rate of evaporation (liquid → vapor) =.
VLE: State of coexistence of L & V phases.The T, P, composition reaches final value which will remain fixed: equilibrium THE NATURE OF EQUILIBRIUM Equilibrium : A static condition in which no changes occur in the macroscopic properties of a system with time. Measures of composition VLE : Qualitative behavior Simple Models for VLE - Raoult’s Law - Dewpoint& Bubblepoint Calculations with Raoult’s Law - Henry’s Law VLE by modified Raoult’s law VLE from K-value correlations.PTT 201/4THERMODYNAMICS SEM 1 (2013/2014) Vapor/Liquid Equilibrium (VLE) Solution Thermodynamic:Ĭhapter Outline (Smith) Nature of Equilibrium