Let’s solve Q.3 and Q.4 step by step.
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Q.3: Label the gases that cause acid rain and the major components of acid rain.
We are given four substances:
- Nitric acid (HNO₃) → This is an *acid* formed in the atmosphere, part of acid rain.
- Nitrogen oxide (NOₓ) → These are *gases* released from cars and factories; they react to form nitric acid.
- Sulphur dioxide (SO₂) → This is a *gas* released from burning coal/oil; it reacts to form sulphuric acid.
- Sulphuric acid (H₂SO₄) → This is an *acid* formed in the atmosphere, part of acid rain.
In the diagram:
→ The
top two red boxes (with arrows going up from factories/power plants into clouds) should be labeled with the
gases that cause acid rain:
- SO₂ (sulphur dioxide)
- NOₓ (nitrogen oxides)
→ The
bottom two red boxes (in the rain falling onto land/water) should be labeled with the
major components of acid rain (the acids themselves):
- H₂SO₄ (sulphuric acid)
- HNO₃ (nitric acid)
So, labeling order (from top to bottom as shown in image):
Top left box (gas rising from factory near mountains):
Sulphur dioxide (SO₂)
Top middle box (gas rising from power plant near river):
Nitrogen oxide (NOₓ)
Bottom right box (rain falling on land):
Sulphuric acid (H₂SO₄)
Bottom lower right box (rain falling into water):
Nitric acid (HNO₃)
*(Note: The exact placement may vary slightly depending on source location — e.g., SO₂ often comes from coal-burning plants, NOₓ from vehicles/engines — but both gases rise and both acids fall in rain.)*
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Q.4: What is the pH of pure (unpolluted) rainwater?
Pure rainwater is not neutral (pH 7). Why? Because carbon dioxide (CO₂) in the air dissolves in rainwater to form weak carbonic acid (H₂CO₃), which makes it slightly acidic.
The natural pH of unpolluted rainwater is about
5.6.
So correct answer:
b) about 5.6
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Final Answer:
Q.3 Labels (top to bottom, left to right as per diagram flow):
- Top left gas box: Sulphur dioxide (SO₂)
- Top middle gas box: Nitrogen oxide (NO)
- Bottom right rain box: Sulphuric acid (H₂SO₄)
- Bottom lower right rain box: Nitric acid (HNO)
Q.4: b) about 5.6
Parent Tip: Review the logic above to help your child master the concept of acid rain worksheet.
