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This question is about atmospheric pollution - AQA - GCSE Chemistry - Question 6 - 2020 - Paper 2
Question 6
This question is about atmospheric pollution. Figure 3 shows a limestone carving which has been damaged by atmospheric pollution. The carving has been: • blackene... show full transcript
Worked Solution & Example Answer:This question is about atmospheric pollution - AQA - GCSE Chemistry - Question 6 - 2020 - Paper 2
Step 1
Explain why soot is formed when some fossil fuels are burned.
Answer
Soot is formed during the combustion of fossil fuels due to incomplete combustion. When there is insufficient oxygen available during the burning process, it leads to the formation of carbon particles, which manifest as soot.
Step 2
Explain how reducing the amount of sulfur in fossil fuels reduces the erosion of limestone.
Answer
When fossil fuels are burned, sulfur reacts with oxygen to form sulfur dioxide ( ext{SO}_2). If the amount of sulfur is reduced, less sulfur dioxide is emitted into the atmosphere. Consequently, this leads to less acid rain, which is formed when sulfur dioxide reacts with water in the air. As there is less acid rain, the erosion of limestone is minimized since acidic conditions are less prevalent.
Step 3
Explain why oxides of nitrogen are formed in car engines.
Answer
Oxides of nitrogen are formed in car engines when air combines with fuel at high temperatures. In the engine, nitrogen from the air reacts with oxygen, forming nitrogen oxides (NOx). The high temperatures during combustion facilitate this reaction.