Sublimation of Iodine at Various Pressures Multipurpose Experiments in Inorganic and Physical Chemistry

摘要

Iodine is a dark purple(almost black)crystalline solid.It is commonly used as a tincture of iodine;its dark-brown color being due to charge-transfer complexes with the solvent molecules(1).Iodine crystals slowly sublime at room temperature,and when heated they turn into deep-purple vapors.These phenomena are described in many textbooks,and the authors of several articles(2-4)presented various modifications of the experiment.The aim of this article is to elucidate some interesting phenomena that can be observed in the process of heating solid iodine in closed vessels at various pressures and temperatures.The article and questions therein may be used in classroom discussion with students of general,inorganic,and physical chemistry(molecular-kinetic theory).