Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Chemistry
Lesson Topic: Evaluate practical methods for investigating the rate of a reaction including change in mass of a reactant or a product and the formation of a gas
Learning Objective/s:
  • Describe how mass change and gas volume can be used to determine reaction rate.
  • Calculate average rates from mass‑time and volume‑time data.
  • Compare the advantages and limitations of the three practical methods.
  • Design a simple investigation using either mass change or gas collection and identify likely sources of error.
Materials Needed:
  • Analytical balance (±0.01 g)
  • Gas syringe or eudiometer
  • Crucibles, beakers, magnesium ribbon, 1 M HCl
  • Thermometer and water/ice bath
  • Stopwatch
  • Safety goggles, gloves, lab coat
  • Projector/whiteboard for diagrams
 Introduction:
Begin with a quick question: “How could we measure how fast a reaction is happening without a fancy sensor?” Students recall factors that affect rate from previous lessons. Explain that today they will learn three practical ways to quantify rate and will be able to choose the most suitable method for a given reaction.
Lesson Structure:
  1. Do‑now (5’) – Students list three factors that influence reaction rate and submit on sticky notes.
  2. Mini‑lecture (10’) – Review kinetic concepts and introduce the three practical methods (mass of solid, gas volume, mass of liquid).
  3. Demonstration (15’) – Teacher conducts the Mg + HCl mass‑change experiment while students record mass and gas volume at set intervals.
  4. Group activity (20’) – Small groups set up the gas‑volume method, collect data, plot volume vs. time and calculate the average rate.
  5. Comparison discussion (10’) – Groups share results, discuss advantages/limitations of each method and sources of error.
  6. Exit ticket (5’) – Each student writes one advantage and one limitation of the method they found most reliable.
Conclusion:
Recap the key idea that reaction rate can be quantified by tracking mass loss/gain or gas evolution and that method choice depends on the reaction type and equipment. Collect exit tickets as a quick retrieval check. For homework, assign a brief report where students propose a kinetic investigation for a new reaction, justifying their choice of measurement method.