# Top-rated ScreenCasts

Text Section | Link to original post | Rating (out of 100) | Number of votes | Copy of rated post |
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14.09 - Numerical procedures for binary, ternary LLE | Click here. | 100 | 1 |
LLE flash using Matlab/Chap14/LLEflash.m (5:54) (msu.edu) An overview of the LLE flash routine in Matlab, including an overview of the program logic and then an example of how to run the program. See also - Supplement on Iteration of LLE with Excel and Matlab. |

10.02 - Vapor-Liquid Equilibrium (VLE) Calculations | Click here. | 100 | 2 |
VLE Routines - General Strategies (4:49) (msu.edu) Deciding which routine to use is more challenging than it appears. Also understanding the strategy used to solve the problems is extremely helpful in being able to develop the equations to solve instead of trying to memorize them. |

12.04 - The Flory-Huggins Model | Click here. | 100 | 3 |
The Flory and Flory-Huggins Models (7:05) (msu.edu) Flory recognized the importance of molecular size on entropy, and the Flory equation is an important building block for many equations in Chapter 13. Flory introduced the importance of free volume. The Flory-Huggins model combines the Flory equation with the Scatchard-Hildebrand model using the degree of polymerization and the parameter χ. The Flory-Huggins model is used widely in the polymer industry. Comprehension Questions: Assume δ for polystyrene, where _{S}δ is the solubility parameter for styrene. Also, polystyrene typically has a molecular weight of about 15,000. Room temperature is 25°C._{S}1. Estimate the infinite dilution activity coefficient of styrene in polystyrene. |

08.07 - Implementation of Departure Functions | Click here. | 100 | 2 |
Derive the internal energy departure function (uakron.edu, 20min) for the following EOS: Comprehension: Given ( /_{TV}RT = -2ln(1-η) - 16.49_{P}η/[1-_{P}βεβε(1-2η)/(1+2_{P}η)^2 ]_{P}1. Derive the internal energy departure function. 2. Derive the expression for the compressibility factor. 3. Solve the EOS for Zc. |

05.4 - Refrigeration | Click here. | 100 | 2 |
Refrigeration Cycle Introduction (LearnChemE.com, 3min) explains each step in an ordinary vapor compression (OVC) refrigeration cycle and the energy balance for the step. You might also enjoy the more classical introduction (USAF, 11min) representing your tax dollars at work. The musical introduction is quite impressive and several common misconceptions are addressed near the end of the video. |

14.10 Solid-liquid Equilibria | Click here. | 100 | 3 |
Solid-liquid Equilibria using Excel (7:38min, msu) The strategy for solving SLE is discussed and an example generating a couple points from Figure 14.12 of the text are performed. Most of the concepts are not unique to UNIFAC or Excel. This screeencast shows how to use the solver tool to find solubility at at given temperature. |

05.2 - The Rankine cycle | Click here. | 100 | 1 |
Rankine Cycle Introduction (LearnChemE.com, 4min) The Carnot cycle becomes impractical for common large scale application, primarily because H2O is the most convenient working fluid for such a process. When working with H2O, an isentropic turbine could easily take you from a superheated region to a low quality steam condition, essentially forming large rain drops. To understand how this might be undesirable, imagine yourself riding through a heavy rain storm at 60 mph with your head outside the window. Now imagine doing it 24/7/365 for 10 years; that's how long a high-precision, maximally efficient turbine should operate to recover its price of investment. Next you might ask why not use a different working fluid that does not condense, like air or CO2. The main problem is that the heat transfer coefficients of gases like these are about 40 times smaller that those for boiling and condensing H2O. That means that the heat exchangers would need to be roughly 40 times larger. As it is now, the cooling tower of a nuclear power plant is the main thing that you see on the horizon when approaching from far away. If that heat exchanger was 40 times larger... that would be large. And then we would need a similar one for the nuclear core. Power cycles based on heating gases do exist, but they are for relatively small power generators. |

07.06 Solving The Cubic EOS for Z | Click here. | 100 | 2 |
6. Solving for density (uakron.edu, 9min) An alternative to solving directly for Comprehension Questions: 1. Solve for the liquid density (mol/cm3) of n-pentane at 62C and 2.5 bars using the vdW EOS. |

08.08 - Reference States | Click here. | 100 | 1 |
Peng-Robinson Properties - Excel (6:56) (msu.edu) Provides an overview of using the Peng-Robinson spreadsheet Preos.xlsx for calculation of H, U, S and use of solver. Comprehension Questions: 1. For liquid propane at 298K and 1 MPa, and a reference state of 298K and 1bar propane vapor, what is the ideal gas contribution to "H-H |

17.07 - Temperature Dependence of Ka | Click here. | 100 | 2 |
Example 17.4 and 17.5 solved using Kcalc.xlsx (6:01) (msu.edu) The full form of the temperature dependence of Ka is implemented in Kcalc.xlsx and Kcalc.m. This screecast covers the use of Kcalc.xlsx for Example 17.4 and Example 17.5 of the textbook. Comprehension Questions: 1. CO and H2 are fed in a H. _{R}º2. CO and H2 are fed in a 1:1 ratio to a reactor at 500K and 20 bars with a catalyst that favors only CH3OH as its product. Calculate ΔG and Δ_{R}ºH._{R}º3. CO and H2 are fed in a 1:1 ratio to a reactor at 600K and 20 bars with a catalyst that favors only CH3OH as its product. Calculate ΔG and Δ_{R}ºH._{R}º4. CO and H2 are fed in a 1:1 ratio to a reactor at 500K and 20 bars with a catalyst that favors only CH3OH as its product. Calculate ΔG and Δ_{T}ºH. Check your answer for Δ_{T}ºGusing the value given for _{T}º Kin Example 17.1._{a }5. CO and H2 are fed in a 1:1 ratio to a reactor at 600K and 10 bars with a catalyst that favors only CH3OH as its product. Calculate K, Δ_{a}G and Δ_{T}ºH. _{T}º6. CH3OH is fed to a reactor at 200 ºC and 1 bar with a catalyst that produces CO and H2. Calculate K, Δ_{a}G and Δ_{T}ºH for this reaction and compare to the literature values given in Example 17.6 of Section 17.10._{T}º7. CH3OH is fed to a reactor at 300 ºC and 1 bar with a catalyst that produces CO and H2. Calculate K for this reaction and compare to the value given in Example 17.6 of Section 17.10. Give two reasons why the two estimates are not identical._{a} |