Partial Molar Quantities: Interactive Simulation
This simulation runs in your browser. Try to predict the behavior when a parameter changes before using a slider to change that parameter. A screencast below explains how to use this simulation.
Simulation: Partial Molar Enthalpy
The molar enthalpy of a binary mixture of A and B is plotted as a function of the mole fraction of component A. The end points of the molar enthalpy are the pure-component enthalpies HA and HB. The partial molar enthalpies, \(\overline{H}_A\) and \(\overline{H}_B\), are obtained by drawing a tangent line at the black point (indicating the mole fraction of the solution). The intersections of this tangent with the y axis at xA = 0 and xA = 1 correspond to the partial molar enthalpies of B and A, respectively. You can change the mole fraction of A in the mixture with the slider. For an ideal solution (non-ideal parameter = 0), the enthalpy of the mixture is a linear function of the molar enthalpies of the pure components. For a non-ideal solution, you can vary a parameter that represents the deviation from ideality.
Try to answer these questions before determining the answer with the simulation. We suggest that you write down the reasons for your answers.
- For the figure below with the non-ideal parameter of 50, approximately what is the maximum value of the partial molar enthalpy of A?
- As the mole fraction of A increases, what does the partial molar enthalpy approach?
- What does the enthalpy versus mole fraction plot look like for an ideal binary solution?