09.07 - Calculation of Fugacity (Gases)

We occasionally require the fugacity in the vapor phase by an EOS other than the PR EOS. (learncheme, 3min) This becomes especially common in Unit 3 when we extend our methods to mixtures. Another skill demonstrated in this screencast is a sample derivation using the pressure dependent formulas. Note that there is a typo in the initial problem statement. The equation of state should be: PV = (1-0.05 P)RT.

Comprehension Questions:

1. Rearrange the given EOS to solve for Z and apply Eq. 9.23 to solve for the change in fugacity. Compare your answer to that given in the screencast. Which method seems easier to you?
2. Use Eq. 7.5 with Eq. 9.23 to derive an expression for the fugacity.
3. Apply the result of #2 to evaluate the fugacity of n-pentane at 398 K and 1 MPa.
4. Does this condition for pentane satisfy Eq. 7.10? Explain.