In this activity, students will investigate how temperature, activation energy, initial amounts of products and reactants, and type of reaction (exo- or endothermic) effect the equilibrium position of a reaction using a simulation.
AP Chemistry Curriculum Framework
- Big Idea 6: Any bond or intermolecular attraction that can be formed can be broken. These two processes are in a dynamic competition, sensitive to initial conditions and external perturbations.
- 6.8 The student is able to use Le Chatelier’s principle to predict the direction of the shift resulting from various possible stresses on a system at chemical equilibrium.
By the end of this lesson, students should be able to
- See how temperature affects the value of equilibrium constants for endothermic and exothermic reactions.
- See how activation energy affects.
This lesson supports students’ understanding of
- Equilibrium constant
- Activation energy
Teacher Preparation: 10 minutes
Lesson: one class period
For each group:
- Computer with access to the internet
No safety precautions need to be observed during this activity.
- This lesson is used to reinforce how the concepts of equilibrium and thermodynamics are connected to one another.
- Have students visit: http://phet.colorado.edu/en/simulation/reversible-...
For the Student
Complete the following table using the simulator.
Determine whether you want to test an exo- or endothermic reaction. Change the E a and T, one variable at a time, keeping the other variables constant.
Type of reaction (endo/exo)
K (equilibrium constant)
- How does changing Ea affect the reaction? Explain.
- How do changes in T affect the value of K?
- Is the reaction A → B endothermic or exothermic? Explain.
- How do you know when equilibrium is established?
- Describe the conditions of a reversible reaction you conduct using the simulator. How do you know it is reversible?