Week 11 Reflection

During chemistry class this past week, the class split up into pairs and each small group was to make a thermos. Throughout the planning stages, my partner and I ran into the dilemma on what to use to insulate our cup. One of my suggestions was that we use a chemical heat pack that I possessed and wrap it around the cup to heal seal the energy in. Our problem was that this pack radiates energy when the coin on the inside of it was snapped to cause the mixture on the inside to crystallize and give off energy; it is not like your standard heating pack/source, for it creates its own energy instead of recieving it from an external source, such as an outlet. After discussing this with Mr. Abud, he suggested that we make two thermoses: one with the chemical heat pack wrapped around it and the other made the standard, acceptable materials. Our first thermos, the chemical heat pack, was fairly simple to assemble and recquired few materials. In order to build this thermos, we surrounded a styrofoam cup with the chemical heat pack and used electrical tape to secure it into place. As for our second thermos, its design was a bit more complex than the other. When building this thermos, we constructed it by taking a cardboard box and cutting out holes in a thick roll of foam that were made to fit the styrofoam cup. After placing the cup in the middle of the holes, we used a hot glue gun to glue styrofoam packaging peanuts and adhesive stryofoam to the cup to further insulate it. From there, we sealed off the top of the cup using more hot glue to stick a thin cardboard slab covered in adhesive foam over the opening.

From then on, we were able to test out both of our thermos by adding 350 mL of boiling water to our cups and recording its temperature every minute. Each measurement was taken in degrees Celsius, but had to be converted to degrees Kalvin for this experiment. Once both trials of each thermos had been recorded, my partner and I were able to compare the results of each of the thermos to help us come to the conclusion on which thermos more effectively retained energy. Much to our surprise, the thermos with the styrofoam cup surrounded by foam chunks had done a better job of retaining energy that the one with the chemical heat pack around it. We had assumed that since there was a small amount of heat being added to the system, that would've helped the cup keep the water hotter for longer. Its failure to outshine the other thermos was most likely due to the fact that the chemical heat pack thermos was not sealed off very well, therefore allowing energy to escape out of the system. Another thing we ran into along the course of the experiment was that the water was never at the temperature we hoped for when it was poured into the styrofoam cups. It was always a few degrees cooler, slightly throwing off our data planning and making it a bit more difficult to record data for this experiment.