Lesson Plan

Lesson Plan
Grade: Date: 25/02/2026
Subject: Chemistry
Lesson Topic: State the symbol equation for the conversion of sulfur dioxide to sulfur trioxide in the Contact process, $2 \mathrm{SO}_2(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g}) \rightleftharpoons 2 \mathrm{SO}_3(\mathrm{~g})$
Learning Objective/s:
  • State the balanced symbol equation for the conversion of SO₂ to SO₃ in the Contact process.
  • Explain how changes in concentration, temperature, pressure, and catalyst affect the equilibrium position.
  • Apply Le Châtelier’s principle to predict the effect of varying conditions on SO₃ yield.
  • Interpret equilibrium tables to determine the direction of shift.
  • Solve typical exam questions involving the Contact process equilibrium.
Materials Needed:
  • Projector or interactive whiteboard
  • Slides/PowerPoint on the Contact process
  • Handout with equilibrium tables and practice questions
  • Whiteboard markers and chart paper
  • Diagram of energy profile (printed or digital)
  • Clickers or online quiz tool for quick checks
Introduction:
Begin with a quick recall question: “What is the balanced equation for the Contact process?” Connect this to students’ prior knowledge of reversible reactions and set the success criteria – students will be able to write the equation and explain how conditions shift equilibrium.
Lesson Structure:
  1. Do‑now (5') – Students write the balanced equation from memory; teacher collects a few responses.
  2. Mini‑lecture (10') – Review reversible reactions and Le Châtelier’s principle using slides.
  3. Guided analysis (12') – Work through the equilibrium table; predict effects of changing pressure, temperature, and concentrations.
  4. Demonstration/video (8') – Short animation of the Contact process and V₂O₅ catalyst action.
  5. Collaborative worksheet (10') – Groups answer questions on how each factor shifts the equilibrium; share answers.
  6. Exit ticket (5') – Write: “If pressure is increased, what happens to SO₃ yield and why?”
Conclusion:
Recap the key points: the balanced equation, the factors that shift equilibrium, and the direction of shift for each. Collect the exit tickets as a retrieval check and assign a short homework task to complete a set of equilibrium‑shift problems.