#### Ternary Phase Diagrams: Interactive Simulations

The first simulation will run on your browser. The other two simulations were prepared using Mathematica. Download the free Wolfram player, and then download the simulation CDF file (link given below or click on figure to download). Try to predict the behavior when a parameter changes before using a slider to change that parameter. Screencasts below explain how to use these simulations.

##### Simulation: Basic Ternary Phase Diagram

This demonstration shows two representations of a ternary phase diagram for three-component mixtures. The black point, which can be moved to any location within the triangle by clicking that location, represents the mixture composition, and each corner of the triangle is a pure component. The fraction of the distance from the base to the corner is the mass fraction of that component.

**Try to answer this question before determining the answer with the simulation**. We suggest that you write down the reasons for your answer.

- Where is the point on the equilateral ternary phase diagram that represents a mixture with x
_{A}= 0.2, x_{B}= 0.5, and x_{C}= 0.3?

##### Simulation: Ternary Phase Diagram with Phase Envelope

This demonstration shows a ternary phase diagram with a phase envelope. This diagram represents the phase behavior of ternary mixtures that are only partially miscible so that phase separation occurs. The black point, which can be moved to any location within the triangle by clicking on that location, represents the overall composition of the mixture. Each corner of the triangle corresponds to a pure component. In the view diagram mode, grey tie lines are shown in the two-phase region when the show tie lines option is selected. The endpoints of each tie line correspond to the compositions of the two phases in equilibrium (α and ß phases), and these compositions are shown when the show α phase and show ß phase options are selected.

**Try to answer this question before determining the answer with the simulation**. We suggest that you write down the reasons for your answer.

- Two phases are in equilibrium and one of the phases has a mass fraction of 0.7 for component C in the diagram below. What is the mass fraction of C in the second phase that is in equilibrium with this phase?

This Demonstration shows a ternary phase diagram that has a phase envelope. This diagram is used to represent the phase behavior of mixtures of three components that are only partially miscible over a range of compositions so that phase separation occurs. In the “view diagram” option, the black point, which can be moved to any location within the triangle by clicking on that location, represents the overall composition of the mixture. Each corner of the triangle corresponds to a pure component. When the black point is in the two-phase region, a tie line (large-dash black line) is shown, and the endpoints of the tie line correspond to the compositions of the two phases (α, β) that are in equilibrium. The points along the left of the phase envelope boundary belong to the α phase, and the points along the right belong to the β phase.

**Try to answer this question before determining the answer with the simulation**. We suggest that you write down the reasons for your answer.

- Two liquid phases are in equilibrium. One phase has a mass fraction of component B of 0.6. Using the diagram below, what is the mass fraction of component B in the second phase?