We want to analyze step (b) in fnt 1-3 (triggering) more closely using the energy-added diagram of the three phase model of pure substances. this will us get a deeper understanding of this part of the process and will enable us to extend the three phase model of pure substances to make it more realistically explain actual phenomena. (it turns out that super cooling and super-heating are rather common. usually, however, they occur over a very small temperature range and thus go unnoticed.) but first, we need to compare the cooling in process (a) to the heating in the combined process (d) and (e). we will use the graphs you make here to do this in dl activity 1.5 i. sketch a temperature vs. energy added diagram for sodium acetate going between room temperature and 100 c. this is the combined process (d) and (e) from fnt 1-3. i. on a new diagram drawn exactly below the one you drew in i., sketch the path representing the process of the liquid heat pack cooling down from 100 'c to room temperature with no phase change (assuming there is supercooling as you observed). check that the path you sketched makes sense by verifying that the changes in temperature and energy shown on the diagram as you move along the path you sketched match what you know about the actual changes in temperature and energy of the heat pack as it cools to room temperature without changing phase from liquid to solid. this is process (a) in fnt 1-3, and the diagram should look like the one you drew for process (a)