Collapsing the can. Fill an empty soda can with about 20 mL of water. Using tongs, heat the can over a Bunsen burner until steam is readily generated and the can is filled with vapor. Quickly invert the can into a container containing ice water. Before we begin let's review the terms endothermic, exothermic, hydrate, and anhydrous.
Exothermic reactions release energy into the environment - feel hot.
CaO is hygroscopic. You must have the anhydrous form. In group work areas have crucibles with DRY CaO, water bottles, and paper towels. You will be working in your study groups for this observation. Record consensus observation.