Top-rated ScreenCasts
| Text Section | Link to original post | Rating (out of 100) | Number of votes | Copy of rated post |
|---|---|---|---|---|
| 12.07 Multicomponent Extensions of van Der Waals' Models | Click here. | 80 | 1 |
M1/MAB Extension of the Multicomponent Flash Spreadsheet (19min, uakron.edu) adapted from Ideal Solutions (cf Section 10.4) Shows how to modify the spreadsheet created for Ideal Solutions (Section 10.4) to apply modified Raoult's law for 5 components using the M1/MAB model. Note: This is a companion file in a series. You may wish to choose your own order for viewing them. For example, you should implement the first three videos before implementing this one. Also, you might like to see how to quickly visualize the Txy analog of the Pxy phase diagram. If you see a phase diagram like the ones in section 11.8, you might want to learn about LLE phase diagrams. The links on the software tutorial present a summary of the techniques to be implemented throughout Unit3 in a quick access format that is more compact than what is presented elsewhere. Some students may find it helpful to refer to this compact list when they find themselves "not being able to find the forest because of all the trees." Comprehension Questions: |
| 09.05 - Fugacity and Fugacity Coefficient | Click here. | 80 | 2 |
What is fugacity? (10min) (learncheme.com) Defines fugacity in terms of Gibbs Energy and describes the need for defining this new property as a generalization of how pressure affects ideal gases. |
| 13.03 - NTRL | Click here. | 80 | 1 |
NRTL concepts (2:30) (msu.edu) The concepts on the development of the NRTL activity coefficient model. Comprehension Questions: 1. What value does the NRTL model assume for the coordination number (z)? |
| 09.05 - Fugacity and Fugacity Coefficient | Click here. | 80 | 2 |
In a contest for "the most hated word in Chemical Engineering," fugacity won by a landslide. This video (15min, uakron.edu) reviews how the term was developed and why it's not really as bad as all that. In fact, it's a nice word that sets the stage for all of phase and reaction equilibrium with a straightforward extension of the same conceptual basis to mixtures. On second thought, perhaps the power of that conceptual basis and all that it implies is what really intimidates new students. Many perspectives have been offered to help overcome the frustration that students feel toward fugacity. If you like a comic book perspective, even that is available. Comprehension Questions: 1.What is the fugacity of a vapor phase component in a mixture according to Raoult's law? |
| 13.04 - UNIQUAC | Click here. | 80 | 4 |
UNIQUAC concepts (6:44) (msu.edu) Concepts and assumptions used in developing the UNIQUAC activity coefficient method. This method introduced the use of surface area as an important quantity in calculation of activity coefficients. |
| 01.2 Molecular Nature of Temperature, Pressure, and Energy | Click here. | 76.962 | 79 |
Molecular Nature of Energy and Temperature (msu.edu) (3:34) Comprehension Questions: 1. A 1m3 vessel contains 0.5m3 of saturated liquid in equilibrium with 0.5 m3 of saturated vapor. Which molecules are moving slower? (a) the vapor (b) the liquid (c) they are all the same. 2. A glass of ice water is sitting in your freezer, set to 0C and fully equilibrated. Which molecules are moving slower? (a) the gas (b) the liquid (c) the solid (d) they are all the same. 3. You walk into the kitchen in the morning to get some breakfast. The ceiling fan is on. You forgot your slippers. Which one is "hotter?" (a) the floor (b) the ceiling (c) the granite counter top (d) the air in the room (e) they are all the same. |
| 12.01 - The van der Waals Perspective for Mixtures | Click here. | 76.6667 | 6 |
Mixing Rules (7:23) (msu.edu) How should energy depend on composition? Should it be linear or non-linear? What does the van der Waals approach tell us about composition dependence? This screencasts shows that the mixing rule for 'a' in a random mixture should be quadratic. A linear mixing rule is usually used for the van der Waals size parameter. |
| 12.03 - Scatchard-Hildebrand Theory | Click here. | 74.5455 | 11 |
Scatchard-Hildebrand Theory (6:53) (msu.edu) Have you ever heard 'Like dissolves like'? Here we see that numerically. The Scatchard-Hildebrand model builds on the van Laar equation by using pure component information. Scatchard and Hildebrand replaced the energy departure with the experimental energy of vaporization. Because this is related to the 'a' parameter in the van Laar theory, they developed a parameter called the 'solubility parameter', but based it on the energy of vaporization. Interestingly, the model reduces to the one parameter Margules equation when the molar volumes are the same. Comprehension Questions: 1. Based on the Scatchard-Hildebrand model, arrange the following mixtures from most compatible to least compatible. (a) Pentane+hexane, (b) decane+decalin, (c) 1-hexene+dodecanol, (d) pyridine+methanol, _____ ______ ______ ______ |
| 02.01 Expansion/Contraction Work | Click here. | 73.3333 | 3 |
Vocabulary in Sections 2.1-2.3: Forms of "Work." (uakron.edu, 11 min) Making cookies is hard work. In discussing work, we develop several shorthand terms to refer to specific common situations: expansion-contraction work, shaft work, flow work, stirring work, "lost" work. These terms comprise the headings of sections 2.1-2.3, but it is convenient to discuss them all at once. The important thing to remember is that work is really just force times distance, pure and simple. The shorthand terms are not intended to complicate the discussion, but to expedite the analysis of the energy balance. Developing some familiarity with the terms related to common daily experiences may help you to assimilate this new vocabulary. Sample calculations (13min) illustrate a remarkable difference when one is faced with gas compression vs. liquid pump work. Comprehension Questions: |
| 08.01 - The Departure Function Pathway | Click here. | 73.3333 | 6 |
Departure Function Overview (11:22) (msu.edu) |