Feel the Heat - Student Exploration Gizmo

Name: Bella Eckhardt Date: 5/8/25 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? ​ ​ The vibrations make the heat 2.​ Where do you think the “cold” and the heat comes from? ​ The cold comes from the outside 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. 1.​ Did the temperature go up or down? up 2.​ Experiment with different powders until you find one that produces the opposite effect. What powder did you use? NH4NO3 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. Some powders don’t produce a temperature change at all. When energy changes do occur, they can be put to good use. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved Get the Gizmo ready: Activity A: Molecular view ●​ Click Reset ( ). ●​ Drag a bottle of NaC2H3O2 from the shelf. Introduction: The reactions in this activity are performed within a calorimeter, an insulated device that keeps heat from escaping, enabling you to accurately record temperature changes. Question: Why does the temperature change when a powder is dissolved in water? 1.​ Observe: Turn on Show molecular view, and notice the water molecules. Set the Water volume to 100 mL and the Powder mass to 20 g, and then click Play. Click Pause ( ) after adding the powder. You should now see show some sodium acetate in the water. A.​ What color represents the bonds between the particles of NaC2H3O2? Purlple B.​ Click Play. Watch the animation a few times. What happens to the NaC2H3O2 bonds? ​ ​ They break down C.​ What happens to the bonds between water molecules? ​ ​ ​ ​ They break apart D.​ What color are the new bonds that form between the solute and solvent? ​ ​ Orange 2.​ Investigate: In the animation, the purple arrows represent energy that is being absorbed from the water, while the orange arrows show energy that is being released into the solution. A.​ Replay the animation, carefully noting the purple arrows. What does this absorbed energy do? ​ They point to the orange and then they disappear B.​ Now replay the animation but focus on the orange arrows. What occurs every time an orange arrow is released? A white bond Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved ​​ C.​ Fill in the blanks: When bonds are broken, energy is When new bonds form, energy is absorbed released D.​ Based on the arrow sizes, do you think more energy is absorbed in breaking bonds, or is more energy released when new bonds form? More energy is released E.​ Which bonds do you think are stronger, the bonds that are broken or the bonds that are formed? Explain your reasoning. Bonds are formed 3.​ Infer: Drag a bottle of KCl from the shelf. Add 20 g of KCl to 100 mL of water. Click Play and look once again at the molecular view. A. Did the temperature rise or fall? fall B. Compare the purple and orange arrows. Does more energy go into breaking bonds, or is more energy released when new bonds form? breaking ​ ​ ​ C ​ Which bonds are stronger: the bonds formed or the bonds broken? broken Explain your reasoning. Broken bonds require more energy 4.​ Think and discuss: Based on your observations, why do you think the temperature of the NaC2H3O2 solution rose while that of the KCl solution fell? ​ ​ ​ ​ ​ Energy is released from the KCL while that energy is absorbed by the NaC2H3O2. 5.​ Think and discuss: If a solute has really strong bonds between its particles, would you expect the resulting solution to get hot or cold? Explain your reasoning. Cold because it needs more energy to break apart the bonds. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved ​​ 6.​ Infer: Some powders produce little to no temperature change when added to water. Find the powder that has the smallest effect on the temperature of the resulting solution. A.​ What is the identity of this powder? ​ NaBr B.​ How do the purple and orange arrows compare? American C.​ For this powder, how do you think the strength of the bonds that are broken compare to those that are formed? The same 7.​ Predict: Set the water to 200 mL and the powder to 1 g. Test each powder, looking only at the molecular view each time. After carefully observing the arrows, predict the following. Which powder do you think will produce the hottest solution?​ CaCl2 Which powder do you think will produce the coldest solution?​ NH4NO3 Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved ​​ Activity B: Test powders Get the Gizmo ready: ●​ Turn off Show molecular view. ●​ Click Reset. Introduction: In order to determine which combination of water and powder will produce the greatest temperature change, it is necessary to perform a controlled experiment. In a controlled experiment only one variable at a time is changed so its effect can be measured. Question: Which combination of powder and water will produce the greatest temperature increase, and which will produce the greatest temperature decrease? 1.​ Experiment: For the first controlled experiment, decide how much water you want to use. Add some powder. Note the temperature change. Keeping the water amount constant, add a different amount of the same powder and note the final temperature. Keep adjusting only the powder amount until you have discovered how it affects the solution temperature. What relationship did you discover between the amount of powder used and the change in temperature? ​ 2.​ Experiment: For the next controlled experiment, repeat the above procedure, except this time keep the amount of powder constant and vary the amount of water. What relationship did you discover between the amount of water used and the change in temperature? ​ Which powder produced the greatest temperature increase? Which powder produced the greatest temperature decrease? ​ How do these results compare to the predictions you made at the end of activity A?​ ​ ​ Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved