Walmart had HotHands on clearance at $0.50 for a two-pack. I bought a bunch for Chemistry labs. The younger kiddos can measure the temperatures of hot and cold packs directly with thermometers. The high school class will do thermochemical labs and use the instant packs for comparison with their results. If one of the teens is miles ahead of the class, he or she can try to devise a hot or cold pack. Now I need a good deal on cold packs, too. I just noticed the hot packs are adhesive backed. I’ll have to watch where the kiddos stick them.
1. Designing a Hand Warmer is intended to AP Chemistry classes, as a project. Make an Instant Cold Pack is easier; most cold packs have urea, ammonium nitrate or calcium ammonium nitrate as ingredients, I like to have commercial products to make comparisons. This version is more of a straight-forward calorimetry lab.
2. Use the heat packs to measure the number of calories; Calories From a Heat Pack has a video and a lesson on calorimetry. Use the same method to determine the number of calories in an instant cold pack.
3. Hot & Cold Packs (1987) is a Chemmatters article, which explains the underlying chemical reactions. Hot and Cold Packs tests exothermic and endothermic reactions. My class will compare results with the instant packs. Spoiler alert! The commercial products are both hotter and colder for much longer periods of time. Here is an instant cold pack lab.
No comments:
Post a Comment