7.01 - Endothermic and Exothermic

1 7.01 Lab/Assessment Directions: Using the data from the table above, draw the potential diagram for each of the three reactions. ●​ 7.01 - Use this video to understand what PE diagrams are. ●​ 7.01 - How to draw the diagrams for this assessment (video) Unless Otherwise Noted All Content © 2022 Florida Virtual School. FlexPoint Education CloudTM is a trademark of Florida Virtual School. 2 [Insert PE diagram #1: synthesis] This graph shows us the energy ups and downs during a chemical reaction. If the products end up with less energy than where the reactants started, it means the reaction actually gave off energy – kind of like burning wood gives off heat. That's what we see here, so this reaction is "exothermic," meaning it's releasing heat. Because energy is being released, we say the change in energy, or "enthalpy," is a negative number, like a loss. Insert PE diagram #2: single replacement] In the first graph, we start with our 'reactants' having a certain amount of energy. Then, the 'products' end up with less energy. Since the products have less energy, it means the reaction must have released energy, like giving off heat. That makes it an exothermic reaction, and because energy was lost from the system, the change in enthalpy would be a negative number Insert PE diagram #3: double replacement] In this second graph, the 'reactants' again start at a certain energy level, and the 'products' end up with a lower energy. So, just like before, if the products are at a lower energy, it means the reaction releases heat. This tells us it's an exothermic reaction, and the enthalpy change would be negative because energy was let out." Unless Otherwise Noted All Content © 2022 Florida Virtual School. FlexPoint Education CloudTM is a trademark of Florida Virtual School. 3 C Conclusion Response: Today I learned that by looking at these energy diagrams, we can tell if a reaction will get hot or cold! If the final products end up with less energy than what we started with, the reaction gives off heat and is called exothermic (like a hand warmer getting warm!). If the products end up with more energy, the reaction sucks in heat and is called endothermic (like an ice pack getting cold!). Unless Otherwise Noted All Content © 2022 Florida Virtual School. FlexPoint Education CloudTM is a trademark of Florida Virtual School.