Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Chemistry
Lesson Topic: Halogenoalkanes: properties, reactions, mechanisms
Learning Objective/s:
  • Describe the general structure and classification of halogenoalkanes.
  • Explain the mechanisms of SN1, SN2, E1, and E2 reactions and the factors that influence them.
  • Predict the major products of nucleophilic substitution and elimination based on substrate, nucleophile/base, and solvent.
  • Apply this knowledge to solve typical examination questions involving mechanisms and reaction conditions.
Materials Needed:
  • Projector or interactive whiteboard
  • PowerPoint slides with reaction mechanisms and tables
  • Handouts of classification table and reaction summary
  • Molecular model kits (for SN2 backside‑attack demonstration)
  • Worksheets with exam‑style questions
  • Markers and whiteboard
 Introduction:
Begin with a quick think‑pair‑share: “What happens when you replace a hydrogen in an alkane with a halogen?” Connect this to prior learning on alkane structures and introduce today’s focus on halogenoalkanes’ properties and reaction pathways. Outline the success criteria: students will be able to name, classify, and predict outcomes of substitution and elimination reactions.
Lesson Structure:
  1. Do‑now (5’) – Short quiz on alkane nomenclature and halogen properties.
  2. Mini‑lecture (10’) – Overview of classification, physical properties, and IUPAC naming using slides.
  3. Mechanism demonstration (15’) – Interactive modelling of SN2 backside attack and SN1 carbocation formation; students predict stereochemical outcomes.
  4. Guided practice (15’) – Small groups work through worksheet problems on SN1/SN2 and E1/E2, using the factors table.
  5. Whole‑class discussion (10’) – Review answers, address misconceptions, and compare rate laws.
  6. Exit ticket (5’) – Students write one condition that favours SN1 versus SN2 and submit.
Conclusion:
Summarise how substrate structure, nucleophile strength, and solvent dictate the pathway of halogenoalkanes. Collect the exit tickets as a retrieval check and assign a set of past exam questions for homework to reinforce mechanism identification.