Comments for Downloading the full package and trial programs

The first of the MathCad programms 'ch2ch2.mcd', can be run directly from this Webpage with MathCad 6.0 (or later) if you have properly installed a reference to Mathcad in your browser. Consult your browser help.- Then you can just click here for Mathcad to open and execute 'ch2ch2.mcd' on the spot. The thermodynamic functions of the Ethene molecule are calculated for the ideal gas (in the harmonic oscillator/rigid rotator approximation) and a range of temperatures in a transparent way and with all necessary comments. Afterwards you may want to run 'ch3ch3gl.mcd' which calculates the equilibrium CH2CH2 + H2 Û CH3CH3 (you first need to download 'ch3ch3.zip' as well. This contains, among the files mentioned below, experimental equilibrium constants to compare your results with).


ch2ch2.mcd for downloading
This MathCad 6.0 file is identical to that which you have downloaded, in case you have clicked 'here' above. If you have not done that, then, by all means, download it now and jot down, where you or your computer placed the file. If your browser "knows" about your installed MathCad executable (use help in the browser's menu) you can click on "open" instead of "save" and run the program directly. Save it afterwards for the next steps.
It serves to calculate the molecular thermodynamic functions, Enthalpy, Gibbs free energy and Entropy as a function of temperature for CH2CH2. This file is identical to the more complete program 'Norotbar.mcd', but preprogrammed with the molecular constants of Ethene. Those can be changed with your own input for any other molecule, that does not have a thermally accessible rotation barrier.

ch3ch3.zip for downloading
Before you try to run either of the next two MathCad-files you have to download and unpack this ZIP-file. Put it into the same directory, usually C:\temp, where ch2ch2.mcd was placed awhile ago. Mathcad will look there for .MCD and auxiliary files.

ch3ch3.mcd for downloading
This file calculates the thermodynamic functions for a molecule with one or more torsional modes in addition to the normal degrees of freedom. Again, this is a file 'Rotbar.mcd', preprogrammed with the molecular data of CH3CH3. In addition the download file 'ch3ch3.zip' contains three tables from K.S. Pitzer & W.D. Gwinn (1942) to handle the partially free torsional modes of molecules like Ethane. You need those for the program to interpolate the necessary corrections to the partition function of the free torsional mode(s).

ch3ch3gl.mcd for downloading
This Mathcad program computes the equilibrium constant as a function of temperature for the reaction
CH2CH2 + H2 Û CH3CH3. You also need the files ch2ch2.prn, h2.prn, and ch3ch3.prn [the results from running ch2ch2.mcd, h2.mcd, and ch3ch3.mcd]. These and the experimental data ethyd.prn are downloaded with the ch3ch3.zip-file.

The complete program package for Statistical Thermodynamics (it contains among many others the above downloads) can be downloaded by clicking here:
Stather.zip