What are 'postive deviations' and 'negative deviations'? What are the 'rules of the game' for working with deviations from Raoult's law?

This screencast show the three main stages of modeling deviations from Raoult's law: 1) obtaining the activity coefficient from experiment; 2) fitting the activity coefficient to an excess Gibbs energy model; 3) using the fitted model to perform bubble, dew, flash calculations. These three stages are often jumbled up when first learning about activity coefficients, so explicit explanation of the strategy may be helpful.

This screencast show application of the Stage I and Stage II calculations using experimental data and the one-parameter Margules equation. It is helpful to follow this screencast with the application of Stage III calculations described in the screencasts for Section 11.2.

## Comments

Lira replied on Permalink

## Modified Raoult's Law and Excess Gibbs Energy (6:27) (msu.edu)

Modified Raoult's Law and Excess Gibbs Energy (6:27) (msu.edu)

What are 'postive deviations' and 'negative deviations'? What are the 'rules of the game' for working with deviations from Raoult's law?

This screencast show the three main stages of modeling deviations from Raoult's law: 1) obtaining the activity coefficient from experiment; 2) fitting the activity coefficient to an excess Gibbs energy model; 3) using the fitted model to perform bubble, dew, flash calculations. These three stages are often jumbled up when first learning about activity coefficients, so explicit explanation of the strategy may be helpful.

Lira replied on Permalink

## Fitting One-Parameter Margules Equation (4:01) (msu.edu)

Fitting One-Parameter Margules Equation (4:01) (msu.edu)

This screencast show application of the Stage I and Stage II calculations using experimental data and the one-parameter Margules equation. It is helpful to follow this screencast with the application of Stage III calculations described in the screencasts for Section 11.2.