Immiscible Liquids Phase Diagrams: Summary
Key points from this module:
- If a liquid is present, it exerts its own saturation pressure, independent of other present immiscible liquid phases.
- The partial pressure of a component in the vapor phase is always less than or equal to its saturation pressure.
- When a vapor mixture is cooled or its pressure is increased, one component will condense first unless the vapor mole fractions are proportional to their saturation pressures.
- For a given temperature, two liquids are in equilibrium with the vapor phase at only one pressure.
- For a given pressure, two liquids are in equilibrium with the vapor phase at only one temperature.
From studying this module, you should now be able to:
- Construct a pressure-composition diagram at a given temperature for two immiscible liquids, given saturation pressures at that temperature.
- Construct a temperature-composition diagram at a given pressure for two immiscible liquids, given Antoine equations (saturation pressure versus temperature) for each component.
- Determine what phases are present, given temperature, pressure, saturation pressures, and overall compositions.
- Given a vapor composition and saturation pressure data, determine the temperature (at constant pressure) or the pressure (at constant temperature) at which one or more components condenses.