Iodine Element (FULL version)

The "Iodine Element" video is the unabridged version of the participation od N. Alikarnassos Highschool in the video competition "Chemistry Rediscovered organized by the European Young Chemists' Network to honor the 150-year landmark of Periodic Table.
The video features physical, chemical and biological properties of the iodine element.
Music is excerpts from “1812 Overture” by P. I. Tchaikovsky. It was chosen because of some notable parallelisms with our video: “1812 overture” was synthesized in commemoration of important Napoleonic war battles. At the same time, in 1811, iodine was serendipitously discovered during saltpeter preparation which was in need during Napoleonic wars! Moreover, NI3 was first synthesized in 1812!

In the first part we demonstrate the transitions between solid and gaseous states of iodine . The purple iodine fumes as well as the shiny iodine crystals formed make this demonstration experiment really impressive.
Next, we perform a variant of “the iodine clock” reaction(s). It is a classical chemistry experiment in which the abrupt color changes make it suitable both for teaching reaction kinetics and chemistry demonstrations. We timed the color development with pouring making it more spectacular and then we decolorized the solution just to bring the color back after a few seconds!
Digging in biochemistry, we show under the microscope the characteristic coloration, shape and patterns of potato starch granules as stained with iodine/iodide solution (Lugol).
Then we highlight the importance of iodine as a micronutrient in human diet and we show a small part of a titration method for determining supplemented potassium iodide in table salt.
Finally, a tiny amount of the contact explosive nitrogen triiodide is detonated (NI3). (Note: Nitrogen triiodide was synthesized and let dry by the chemistry teacher supervisor.)