MYP Chemistry sample question: Acid rain and air pollution

Burning fossil fuels that contain sulfur releases a gas that contributes to acid rain.

1. (a)Name the gas that is released when sulfur-containing fuels are burned.[1]
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   • • Sulfur dioxide (1)
2. (b)Explain how this gas leads to acid rain.[2]
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   • • It dissolves in water droplets in clouds (and reacts with oxygen) (1)
   • • forming acidic solutions such as sulfurous or sulfuric acid that fall as rain (1)
3. (c)Describe two effects of acid rain.[2]
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   • • Any two: damages limestone and marble buildings and statues; makes lakes acidic and harms fish and other organisms; damages trees and soil
4. (d)Suggest one way to reduce acid rain.[1]
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   • • Any one: remove sulfur dioxide from power-station gases (flue gas desulfurisation); use low-sulfur fuel; use renewable energy instead of fossil fuels (1)

When asked for effects, give a specific example and, where you can, say why it happens (acid reacts with calcium carbonate in limestone).