Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Chemistry
Lesson Topic: Describe the characteristic properties of bases in terms of their reactions with: (a) acids (b) ammonium salts
Learning Objective/s:
  • Describe the characteristic properties of bases when they react with acids, including neutralisation, heat release, and pH change.
  • Explain how strong bases react with ammonium salts to produce ammonia gas and a corresponding salt.
  • Predict the products of base‑acid and base‑ammonium salt reactions using general equations.
  • Interpret laboratory observations (temperature rise, gas evolution, litmus change) to identify these reactions.
Materials Needed:
  • Whiteboard and markers
  • Projector or interactive display
  • Printed worksheets with reaction tables
  • Sample chemicals (NaOH, Ca(OH)₂, KOH, HCl, H₂SO₄, NH₄Cl, (NH₄)₂SO₄, NH₄NO₃)
  • Test tubes, beakers, droppers
  • pH indicator paper or litmus strips
  • Safety goggles and gloves
 Introduction:
Begin with a quick demonstration where a clear solution heats up as sodium hydroxide is added to hydrochloric acid, prompting students to predict what is happening. Recall that acids and bases neutralise each other and that ammonia has a distinctive pungent smell. Explain that by the end of the lesson they will be able to describe these reactions, write the balanced equations, and use observable clues to identify them.
Lesson Structure:
  1. Do‑now (5') – students answer a short question on acid‑base neutralisation from the previous lesson.
  2. Mini‑lecture (10') – present the general neutralisation equation, discuss its exothermic nature and pH shift; show the NaOH + HCl example.
  3. Guided practice (10') – pairs complete a table of base‑acid reactions, predicting products and observable signs.
  4. Demonstration (8') – teacher performs the reaction of NaOH with NH₄Cl, highlighting ammonia evolution and a litmus test.
  5. Interactive activity (12') – groups write balanced equations for given base‑ammonium salt combos and explain the observations; teacher circulates to address misconceptions.
  6. Check for understanding (5') – quick quiz (Kahoot or exit ticket) with three multiple‑choice questions on the two reaction types.
Conclusion:
Summarise that bases neutralise acids to form salts and water, releasing heat, while strong bases react with ammonium salts to liberate ammonia gas and produce a new salt. Ask students to write one example of each reaction on an exit ticket. For homework, assign a worksheet requiring balanced equations and prediction of observable changes for additional base‑acid and base‑ammonium salt pairs.