Lesson Plan

• Describe how alkenes react with bromine, hydrogen (Ni catalyst) and water (acid catalyst).
• Predict and write the displayed formulas of the products for each addition reaction.
• Explain the underlying mechanisms (anti‑addition, syn‑addition, Markovnikov hydration).
• Apply the bromine colour‑change test to identify unsaturation in unknown samples.

• Projector and screen
• Whiteboard and markers
• Printed worksheets with reaction tables
• Molecular model kits
• Bromine solution (small demo bottle)
• Hydrogen gas cylinder with safety setup and nickel catalyst
• Sulphuric acid and steam apparatus
• Safety goggles and lab coats

Begin with a striking video of bromine disappearing when added to an alkene, sparking curiosity about why the colour vanishes. Review students’ prior knowledge of double bonds and unsaturation. State that by the end of the lesson they will be able to describe, predict and explain three key addition reactions of alkenes.

1. Do‑now (5’) – Quick quiz on identifying alkenes vs alkanes.
2. Mini‑lecture (10’) – Recap C=C bond, introduce addition concepts.
3. Demonstration (15’) – Bromine addition to cyclohexene; observe colour loss.
4. Guided practice (10’) – Pairs complete worksheet predicting products for hydrogenation and acid‑catalysed hydration.
5. Group discussion (10’) – Explain anti‑addition, syn‑addition and Markovnikov’s rule.
6. Check for understanding (5’) – Exit ticket: write the product of a given alkene with Br₂.
7. Summary (5’) – Recap key points and link to real‑world applications (e.g., hydrogenation of fats).

Summarise how each reagent transforms the double bond and why the observed changes occur. Collect exit tickets to gauge understanding, and assign homework: complete a worksheet drawing displayed formulas for three new alkene addition reactions.