Temperature-Composition Diagram for Immiscible Liquids

The temperature-composition phase diagram for two immiscible liquids, benzene and water, is at constant pressure. Set the pressure with a slider to change the saturation temperature. Set the overall benzene mole fraction with its slider. The bar graph shows the moles of liquid water (blue), liquid benzene (orange) and vapor (green), which contain both components. The system contains one mole total. You can add heat to change the temperature and the amounts in each phase. At a given pressure, all three phases co-exist at only one temperature. When heat is added at this temperature, one of the liquid phases completely evaporates before the temperature increases.