Lesson Plan

Resources → Subject Notes → Chemistry → Notes
Lesson Plan
Grade: Date: 17/01/2026
Subject: Chemistry
Lesson Topic: Describe how to identify the end-point of a titration using an indicator
Learning Objective/s:
  • Describe the role of indicators in acid‑base titrations and how they signal the end‑point.
  • Select an appropriate indicator based on the expected equivalence‑point pH.
  • Perform a titration procedure to detect the colour change and record the end‑point volume.
  • Evaluate the reliability of the observed end‑point using reproducibility criteria.
  • Apply the recorded volume to calculate the concentration of an unknown solution.
Materials Needed:
  • Burette and stand
  • 250 mL conical flask
  • Standardised acid or base solution (titrant)
  • Sample solution (analyte)
  • Selected indicator (e.g., phenolphthalein, methyl orange)
  • White tile or sheet of paper
  • Lab notebook and pen
  • Projector or screen for demonstration slides
 Introduction:
Begin with a quick demonstration of a colour change in a beaker to spark curiosity. Review students’ prior knowledge of acid‑base reactions and the concept of equivalence point. Explain that today they will learn how to use an indicator to pinpoint the titration end‑point and how this impacts calculation accuracy.
Lesson Structure:
  1. Do‑Now (5'): Students answer a short question on equivalence vs. end‑point on a worksheet.
  2. Mini‑lecture (10'): Explain indicators, pH ranges, and choosing the right one; display the indicator table.
  3. Demonstration (10'): Teacher performs a titration, adding indicator and showing the colour change.
  4. Guided practice (15'): Small groups set up the burette, add indicator, conduct the titration, and record the final volume.
  5. Data analysis (10'): Groups calculate the unknown concentration and discuss reproducibility of the end‑point.
  6. Check for understanding (5'): Quick Kahoot quiz on key concepts.
Conclusion:
Summarise that the end‑point is identified by a distinct, permanent colour change of a suitable indicator. Ask students to write one tip for reliable detection on an exit ticket. Assign homework to research another indicator and its pH range for a different acid‑base system.