# Top-rated ScreenCasts

Text Section | Link to original post | Rating (out of 100) | Number of votes | Copy of rated post |
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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. |

04.09 Turbine calculations | Click here. | 100 | 2 |
Entropy Balances: Solving for Turbine Efficiency Sample Calculation. (uakron.edu, 10min) Steam turbines are very common in power generation cycles. Knowing how to compute the actual work, reversible work, and compare them is an elementary part of any engineering thermodynamics course. Comprehension Questions: 1. An adiabatic turbine is supplied with steam at 2.0 MPa and 600°C and it exhausts at 98% quality and 24°C. (a) Compute the work output per kg of steam.(b) Compute the efficiency of the turbine. 2. A Rankine cycle operates on steam exiting the boiler at 7 MPa and 550°C and expanding to 60°C and 98% quality. Compute the efficiency of the turbine. |

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. |

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} |

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. |

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. |

17.07 - Temperature Dependence of Ka | Click here. | 100 | 2 |
You can customize Kcalc.xlsx (uakron.edu, 17min) to facilitate whatever calculations you may need to perform. This presentation shows how to implement VLOOKUP to automatically load the relevant Hf, Gf, and Cp values. It also shows how to automatically use the Cp/R value when a,b,c,d values for Cp are not available. Finally, it shows how a fairly general table of inlet flows, temperatures, and pressures can be used to set up the equilibrium conversion calculation. The initial set up is demonstrated for the dimethyl ether process, then revised to initiate solution of Example 17.9 for ammonia synthesis. Comprehension Questions: 1. The video shows how the shortcut Van't Hof equation can be written as lnKa=A+B/T. What are the values of A and B for the dimethyl ether process when a reference temperature of 633K is used? |

08.02 - The Internal Energy Departure Function | Click here. | 100 | 1 |
Departure Function Derivation Principles (8:03) (msu.edu) |

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. |

17.06 Determining the Spontaneity of Reactions | Click here. | 100 | 1 |
Which way will a reaction go? (3:40) (msu.edu) When both reactants and products are present in a reactng mixture, the direction the reaction will proceed is not necessarily indicated by the sign of ΔG Comprehension Questions: (Hint: review Example 17.1 before answering.) 1. CO and H2 are fed in a |