Hot Pack, Cold Pack: Why Do Some Chemicals Warm Up and Others Cool Down?
Sim Lesson
Students use the Hot Pack, Cold Pack simulation to dissolve different chemicals in water and compare which release thermal energy (warm up) and which absorb it (cool down). Lesson Purpose Students often think dissolving always warms or always cools. Comparing chemicals shows some processes release thermal energy and others absorb it.
A hand-warmer heats up when you snap it, and an instant cold pack turns icy when you squeeze it, both without a stove or freezer. How can just dissolving a chemical in water make it warmer or colder? In this lesson, you will use the Hot Pack, Cold Pack simulation to dissolve different chemicals and watch the temperature change.
Topics and standards: Science, Energy, Chemistry, Physics, Physical Science, Chemical Compounds, Simulation, Grades 6-8, Thermal Energy, MS-PS1-6, Chemical Reactions & Processes, Matter & Its Interactions, SC.7.P.11.2, 7-PS3-1, 3.2.6-8.F