Endothermic and Exothermic Reactions
Learning Intentions
- To understand the difference between endothermic and exothermic reactions
- To be able to graph the change in energy during a chemical or physical reactions
Notes
Endothermic and Exothermic Reactions (12:20)
Questions
- What is the activation energy for a chemical reaction?
- Draw the graph of potential energy vs. time for the following reactions, and identify each as endothermic or exothermic:
- TNT exploding
- Sweat evaporating
- Baking bread
- Splitting a molecule of nitrogen gas
- Snow forming in clouds
- Watch the following video. What can you say about the activation energy for exploding nitroglicerine?
Free Range Chemistry 37 - Nitroglycerin Bang (2:30) - Why can an endothermic reaction can be dangerous to touch?
- Why can an exothermic reaction can be dangerous to touch?
- In an endothermic reaction, where does the energy come from? Where does it go?
- In an exothermic reaction, where does the energy come from? Where does it go?
- Extension: How does a fridge use endothermic and exothermic state changes to achieve cooling?