Rubber Bands, Free Energy, and Le Chatelier's Principle

In this Activity, students compare the temperature change of a rubber band that is quickly stretched compared to one that is quickly relaxed. They predict what effect the stress of heating will have on a stretched rubber strip and test their prediction. This Activity relates to the concepts of endothermic and exothermic processes, spontaneous and non-spontaneous processes, Le Chatelier's principle, structure-related entropy in polymers, and Gibbs free energy, as well as the interplay of enthalpy and intermolecular forces.