# Top-rated ScreenCasts

Text Section | Link to original post | Rating (out of 100) | Number of votes | Copy of rated post |
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03.1 - Heat Engines and Heat Pumps: The Carnot Cycle | Click here. | 60 | 2 |
Heat Engine Introduction (LearnChemE.com, 6min) introduction to Carnot heat engine and Rankine cycle. The Carnot cycle is an idealized conceptual process in the sense that it provides the maximum possible fractional conversion of heat into work (aka. thermal efficiency, Comprehension Questions: |

05.5 Liquefaction | Click here. | 60 | 2 |
Joule-Thomson Expansion (LearnChemE.com, 7min) describes the Joule-Thomson coefficient - ( Comphrehension Questions: 1. Referring to the table for R134a in Appendix E-12, compute the fraction liquid at 252K after throttling from a saturated liquid at 300K. 2. Referring to the table for R134a in Appendix E-12, compute the fraction liquid at 252K after expanding a saturated liquid at 300K through a reversible turbine. |

10.03 - Binary VLE using Raoult's Law | Click here. | 60 | 2 |
Raoult's Law (5:39) (msu.edu) |

09.10 - Saturation Conditions from an Equation of State | Click here. | 60 | 1 |
We can combine the definition of fugacity in terms of the Gibbs Energy Departure Function with the procedure of visualizing an equation of state to visualize the fugacity as characterized by the PR EOS. (21min, uakron.edu) This amounts to plotting Z vs. density, similar to visualizing the vdW EOS. Then we simply type in the departure function formula. Since the PR EOS describes both vapors and liquids, we can calculate fugacity for both gases and liquids. Taking the reciprocal of the dimensionless density (
Concept Questions:
1. What equation can we use to estimate the fugacity of a compressed liquid relative to its saturation value? |

14.04 LLE Using Activities | Click here. | 60 | 2 |
Txy Phase Diagram Showing LLE and VLE Simultaneously (9min,uakron.edu) The binary Txy phase diagram of methanol+benzene is visualized with k) increases, the LLE boundary crashes into the VLE. It is so exciting that it makes a thermo nerd wax poetic about the "valley of Gibbs."_{ij}Comprehension Questions: 1. The LLE phase boundary moves up as the nonideality increases. Which way does the VLE contribution move? Explain how this relates to the molecules' escaping tendencies. 4. What value of kis required to make the LLE binodal barely touch the VLE at 10 bars?_{ij } |

01.5 Real Fluids and Tabulated Properties | Click here. | 60 | 2 |
Steam Tables (LearnChemE.com) (5:59) calculate enthalpy of steam by interpolation |

11.12 - Lewis-Randall Rule and Henry's Law | Click here. | 60 | 11 |
Introduction to Henry's Law (10:16) (msu.edu) Fugacities are calculated relative to standard state values, and the relations developed earlier in the chapter use a pure fluid standard state. What if the pure fluid does not exist as a liquid when pure? One choice is to use Henry's law. |

03.6 - Energy Balance for Reacting Systems | Click here. | 60 | 1 |
Heat Removal from a Chemical Reactor (uakron, 8min) determines heat removal so that a chemical reactor is isothermal following the pathway of Figure 3.5b using the pathway of Figure 2.6c if a heat of vaporization is involved. The reaction is: N2 + 3H2 = 2NH3 at 350C and 1 bar. The pathway to go from products to the reference condition is to correct for any liquid formation at the conditions of the product stream then cool/heat the products to 25C (the reference temperature), then "unreact" them back to their elements of formation. Summing up the enthalpy changes over these steps gives the overall enthalpy of the reactor outlet stream. The same procedure applied to the reactor inlet gives the overall enthalpy of reactor inlet stream. Then the heat duty of the reactor is simply the difference between the two stream enthalpies. Comprehension Questions: |

07.06 Solving The Cubic EOS for Z | Click here. | 60 | 4 |
2. Solving the PR EOS for Z . (learncheme.com, 5min) Shows how to copy/paste from "Crit.Props" and "IG Cps" to "Props". Then compute some properties. Note: this video incorrectly uses a simple copy/paste instead of "paste special." Therefore, the color of the values on the "Props" tab changes from blue to black. Blue values should indicate values that you can change and black values should indicate cells that you should not alter. If you are having trouble finding a particular compound in the database, try searching for a piece of the name. e.g. if the compound is "nitrous oxide," search for "nitro." Comprehension Questions: 1. What is the value for Zc of nitrous oxide? What is its "abbreviated name?" 2. What is the value of Tc for R1234yf? 3. Estimate the entropy of vaporization of toluene at 383.4K according to the Peng-Robinson EOS. 4. Estimate the entropy of vaporization of ethanol at 0.1MPa according to the Peng-Robinson EOS. Compare to the value you infer from Appendix E. |

11.02 - Calculations with Activity Coefficients | Click here. | 60 | 2 |
This example shows how to predict activity coefficients in Excel using the Margules Acid-Base (MAB) model.(8min, uakron.edu) Sometimes you just need a quick estimate of whether to suspect an azeotrope or LLE or some other anomalous behavior. If the MAB model indicates a possible problem, it's time to go to the library or the lab and validate your model with experimental data. 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 |