| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Chemistry |
| Lesson Topic: Describe an acid-base titration to include the use of a: (a) burette (b) volumetric pipette (c) suitable indicator |
Learning Objective/s:
- Describe the complete procedure of an acid‑base titration using a burette, volumetric pipette and appropriate indicator.
- Explain how the equivalence point is identified and why the chosen indicator is suitable.
- Calculate the concentration of an unknown solution from titration data using stoichiometry.
- Demonstrate safe laboratory practices when handling acids, bases and glassware.
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Materials Needed:
- Burette (50 mL) with stop‑cock
- Volumetric pipette (25 mL) calibrated
- Conical flask (250 mL) and white tile
- Standardised acid or base solution (titrant) and unknown solution (analyte)
- Suitable indicator (e.g., phenolphthalein)
- Lab stand with clamp and wash bottle
- Safety goggles, lab coat and gloves
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Introduction:
Begin with a quick demonstration of a colour change in a beaker to spark curiosity about how chemists determine unknown concentrations. Review that students already know about molarity and acid‑base reactions. Explain that today they will carry out a full titration, noting the role of the burette, pipette and indicator, and that success will be shown by correctly calculating the unknown concentration.
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Lesson Structure:
- Do‑now (5'): Answer a short question on the equivalence point on a worksheet.
- Mini‑lecture (10'): Review titration theory, equipment purpose and safety rules.
- Demonstration (10'): Teacher performs a titration, highlighting rinsing, filling the burette and adding the indicator.
- Guided practice (15'): Pairs set up apparatus, conduct the titration, record initial and final volumes, and repeat twice.
- Calculation activity (10'): Students calculate the unknown concentration from their data and discuss possible errors.
- Check for understanding (5'): Exit‑ticket – write one reason for choosing phenolphthalein as the indicator.
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Conclusion:
Summarise how the burette, pipette and indicator work together to give a reliable concentration measurement. Invite a few pairs to share one source of error they encountered and how they mitigated it. Collect an exit ticket where each student records the calculated concentration of their unknown solution. For homework, assign a worksheet on selecting appropriate indicators for different acid‑base pairs.
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