This module models the Gouy experiment which can take upwards of several hours to complete with a class of students in the real world. In the module, a large electro-magnet is shown and the student is asked to select the voltage for generating the magnet field, then choose an empty tube and weigh it with the magnet switched Off then On, weigh a tube filled to a specified mark with water then choose a calibrant (from 3 standards) and finally a sample (from 6 different Chromium(III) complexes they might prepare in the Laboratory) and repeat the weighings with the power Off then On. An HUD shows the status and eventually gives the summary of all the recorded data. To download the jar file and find more information visit:

http://wwwchem.uwimona.edu.jm/WL/

The link to the module is about halfway down the page just before the heading "Symmetry operations in a 3D world."