Student Exploration: Feel the Heat

Student Exploration: Feel the Heat Directions: Follow the instructions to go through the simulation. Respond to the questions and prompts in the orange boxes. Vocabulary: calorimeter, conductor, controlled experiment, dissolve, endothermic, exothermic, insulator, solute, solution, solvent, surroundings, system Prior Knowledge Questions (Do these BEFORE using the Gizmo.) Eduardo hurts his knee during a basketball game. The trainer applies a cold pack, which gets cold after being squeezed. The next day, Eduardo’s friend Beth is going sledding. Beth buys some hand warmers and puts them into her gloves. All morning, her hands stay toasty warm. 1. How do you think these devices work? 2. Where do you think the “cold” and the heat comes from? Gizmo Warm-up As you saw with the instant cold pack and the hand warmers, some reactions absorb energy while others release it. In the Feel the Heat Gizmo, you will explore these energy changes while making your own hot and cold packs. To begin, select the TEST POWDERS tab. Drag a bottle of NaC2H3O2 (sodium acetate) from the shelf. Using the sliders, decide how much water and powder to add. Note the beginning temperature, and then press Play ( ) to see what happens. 2. Experiment with different powders until you find one that produces the opposite effect. When a powder dissolves in water a solution is formed. The powder is the solute and the water is the solvent. Oftentimes energy changes accompany the formation of a solution. When added to water, some powders cause the resulting solution to get hot, while others make it cold. Name: Date: December 9, 2020 I think you can control it by temperature . I think it comes from the friction you make from both of your hands warmer and cold packs . 1. Did the temperature go up or down? The temperature went up . What powder did you use? I used NH4NO3 ammonium nitrate .