Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Chemistry
Lesson Topic: Describe the manufacture of alkenes and hydrogen by the cracking of larger alkane molecules using a high temperature and a catalyst
Learning Objective/s:
  • Describe the cracking process and differentiate thermal and catalytic cracking.
  • Explain how high temperature and solid‑acid catalysts enable the formation of alkenes and hydrogen.
  • Predict the products of cracking for a given alkane feedstock.
  • Interpret the steps of an industrial catalytic cracking unit and relate conditions to product distribution.
  • Apply the concepts to answer exam‑style questions on alkene manufacture.
Materials Needed:
  • Projector and screen
  • PowerPoint slides with diagrams of cracking units
  • Printed handouts of reaction equations and product tables
  • Worksheet for balancing cracking reactions
  • Model/diagram of a catalytic cracking unit
  • Short video clip of a refinery process
  • Clickers or online quiz tool for quick checks
 Introduction:
Begin with a brief video of a refinery and ask students what they think happens to heavy crude fractions. Connect to prior knowledge of hydrocarbon families and bond energies. State that by the end of the lesson they will be able to describe how temperature and a catalyst produce useful alkenes and hydrogen. Clarify the success criteria: explain the process, predict products, and answer an exam‑style question.
Lesson Structure:
  1. Do‑now (5') – quick recall quiz on alkanes, alkenes, and bond‑breaking energy.
  2. Mini‑lecture (10') – introduce cracking, compare thermal vs catalytic methods, highlight temperature and catalyst roles.
  3. Animated demonstration (8') – show a schematic of a catalytic cracking unit and discuss the solid‑acid catalyst mechanism.
  4. Guided practice (12') – pairs balance a cracking reaction (e.g., C₁₂H₂₆ → C₈H₁₈ + C₄H₈ + H₂) and identify alkene and hydrogen products.
  5. Group analysis (8') – examine the product distribution table; answer questions about yields under different conditions.
  6. Exam question practice (10') – students write a concise answer to “Explain how ethylene is obtained from cracking a heavy alkane,” then peer‑review.
  7. Exit ticket (5') – one‑sentence summary of how temperature and catalyst influence alkene production.
Conclusion:
Recap the key points: high temperature supplies the energy to break C–C bonds, while a solid‑acid catalyst creates carbocation intermediates that steer the reaction toward alkenes and hydrogen. Collect the exit tickets to check understanding, and assign a short homework task to research an alternative cracking technology (e.g., fluid‑catalytic cracking) and compare its conditions to those discussed.