Lesson Plan

• Describe the characteristics of a dynamic equilibrium and how rates of forward and reverse reactions compare.
• Apply Le Chatelier’s principle to predict the direction of shift when a system is stressed (concentration, pressure/volume, temperature, catalyst).
• Calculate equilibrium constants (Kc, Kp) and convert between them using the relationship Kp = Kc(RT)Δn.
• Use the reaction quotient Q to determine whether a system will shift left or right before equilibrium is reached.

• Projector and screen
• Whiteboard and markers
• Printed worksheets with equilibrium problems
• Scientific calculators
• Periodic table handouts
• Small sealed containers (e.g., soda bottles) for a quick demonstration

Begin with the question, “What happens inside a sealed bottle of soda when you shake it?” Connect this to students’ prior knowledge of reversible reactions and rate concepts. State that by the end of the lesson they will be able to explain dynamic equilibrium, predict shifts using Le Chatelier’s principle, and calculate equilibrium constants.

1. Do‑now (5'): Quick quiz on reversible reactions and rate equality.
2. Mini‑lecture (10'): Define dynamic equilibrium; illustrate with the soda bottle demo.
3. Interactive discussion (15'): Le Chatelier’s principle – students suggest stresses and predict shifts; teacher confirms with diagram.
4. Guided practice (15'): Calculate Kc for the N₂ + 3H₂ ⇌ 2NH₃ example; then convert to Kp using Kp = Kc(RT)Δn.
5. Group activity (10'): Given various Q values, decide direction of shift; share reasoning.
6. Exit ticket (5'): One‑sentence summary of how a change in temperature affects an exothermic equilibrium.

Recap the three pillars of chemical equilibrium: equal rates, Le Chatelier’s response, and the quantitative use of Kc/Kp. Collect exit tickets and remind students to complete the worksheet for homework, which includes additional Q‑calculations and a short online quiz.