O Levels/IGCSE Chemistry Lesson Plan 10.3

Section	Details
Objective	– State the composition of clean, dry air.- Identify the sources of major air pollutants.
Activities	– Starter (5 mins): Show a pie chart of air composition and ask: “What makes up the air we breathe?”- Main (25 mins): 1. Explain clean, dry air composition: – 78% nitrogen (N₂), 21% oxygen (O₂), <1% noble gases and CO₂. 2. Discuss sources of air pollutants: – Carbon dioxide: Combustion of carbon-containing fuels. – Carbon monoxide and particulates: Incomplete combustion of carbon-containing fuels. – Methane: Decomposition of vegetation, animal digestion. – Oxides of nitrogen: Car engines. – Sulfur dioxide: Combustion of sulfur-containing fossil fuels.- Plenary (10 mins): Students create a table listing air pollutants and their sources.
Resources	Pie chart of air composition, worksheets, pollution source images.
Time	40 minutes total: 5 mins (Starter) + 25 mins (Main) + 10 mins (Plenary).
Homework	Write a short report on how human activities contribute to air pollution.
Assessment	Worksheet: Match pollutants to their sources.
Past Paper Practice	IGCSE Chemistry 0620/41/M/J/20 Q7(a) – Composition and pollutants in the air.

Section	Details
Objective	– State the adverse effects of air pollutants.- Explain how greenhouse gases cause global warming.
Activities	– Starter (5 mins): Show images of smog, acid rain effects, and discuss their causes.- Main (25 mins): 1. Discuss the effects of air pollutants: – CO₂ and methane: Global warming → climate change. – CO: Toxic gas harmful to humans. – Particulates: Respiratory issues and cancer. – Oxides of nitrogen and sulfur dioxide: Acid rain, respiratory problems, smog. 2. Explain global warming: – Greenhouse gases absorb and re-emit thermal energy. – Reduces thermal energy loss to space. – Leads to rising temperatures and climate change.- Plenary (10 mins): Students complete a cause-and-effect diagram linking pollutants to their environmental effects.
Resources	Images of environmental effects, videos on global warming, worksheets.
Time	40 minutes total: 5 mins (Starter) + 25 mins (Main) + 10 mins (Plenary).
Homework	Write a paragraph on how reducing methane emissions can mitigate climate change.
Assessment	Worksheet: Identify the effects of air pollutants and explain their impact.
Past Paper Practice	IGCSE Chemistry 0620/41/O/N/21 Q7(b) – Effects of air pollutants and greenhouse gases.

Section	Details
Objective	State and explain strategies to reduce climate change and acid rain.
Activities	– Starter (5 mins): Ask: “What actions can we take to reduce air pollution?”- Main (25 mins): 1. Discuss strategies to combat climate change: – Planting trees. – Reducing livestock farming. – Decreasing fossil fuel use. – Using hydrogen and renewable energy sources. 2. Explain strategies to reduce acid rain: – Catalytic converters in vehicles. – Using low-sulfur fuels. – Flue gas desulfurisation with calcium oxide.- Plenary (10 mins): Students match strategies to the problems they address (climate change or acid rain).
Resources	Diagrams of catalytic converters, videos on renewable energy, worksheets.
Time	40 minutes total: 5 mins (Starter) + 25 mins (Main) + 10 mins (Plenary).
Homework	Research one renewable energy source and explain how it helps reduce climate change.
Assessment	Worksheet: Match strategies to the environmental issues they address.
Past Paper Practice	IGCSE Chemistry 0620/41/M/J/19 Q7(c) – Strategies to reduce air pollution.

Section	Details
Objective	– Describe photosynthesis and write its word and symbol equations.- Explain how catalytic converters reduce air pollution.
Activities	– Starter (5 mins): Show a green plant and ask: “How does this plant help reduce carbon dioxide in the air?”- Main (25 mins): 1. Explain photosynthesis: – Reaction between carbon dioxide and water to form glucose and oxygen. – Requires chlorophyll and light energy. 2. Word equation: Carbon dioxide + water→Glucose + oxygen\text{Carbon dioxide + water} → \text{Glucose + oxygen}. 3. Symbol equation: 6CO2+6H2O→C6H12O6+6O26\text{CO}_2 + 6\text{H}_2\text{O} → \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2. 4. Discuss catalytic converters: – Reduce NOx\text{NO}_x and CO emissions by converting them to N2\text{N}_2 and CO2\text{CO}_2. – Reaction: 2CO+2NO→2CO2+N22\text{CO} + 2\text{NO} → 2\text{CO}_2 + \text{N}_2.- Plenary (10 mins): Students balance the photosynthesis and catalytic converter equations.
Resources	Plant diagram, catalytic converter images, worksheets, videos.
Time	40 minutes total: 5 mins (Starter) + 25 mins (Main) + 10 mins (Plenary).
Homework	Write a short essay on the importance of photosynthesis for maintaining air quality.
Assessment	Worksheet: Balance and explain photosynthesis and catalytic converter equations.
Past Paper Practice	IGCSE Chemistry 0620/41/O/N/20 Q7(a) – Photosynthesis and air pollution reduction.

Air Composition:
- 78% nitrogen, 21% oxygen, <1% noble gases and CO₂.
Air Pollutants and Effects:
- CO₂ and methane: Global warming.
- CO: Toxic gas.
- Particulates: Respiratory issues, cancer.
- NOx\text{NO}_x and SO2\text{SO}_2: Acid rain, smog, respiratory problems.
Reduction Strategies:
- Plant trees, use renewable energy, catalytic converters, flue gas desulfurisation.
Photosynthesis:
- 6CO2+6H2O→C6H12O6+6O2\text{6CO}_2 + 6\text{H}_2\text{O} → \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2.

Use visual aids like pie charts, diagrams, and videos to make abstract concepts tangible.
Encourage student discussions on real-world implications of climate change and air pollution.
Provide opportunities for students to analyze data and write balanced chemical equations.