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This question is about emissions of oxides of nitrogen from petrol and diesel engines - AQA - A-Level Chemistry - Question 1 - 2020 - Paper 3
Question 1
This question is about emissions of oxides of nitrogen from petrol and diesel engines. 1. Explain how oxides of nitrogen are formed in engines. 2. State why it is ... show full transcript
Worked Solution & Example Answer:This question is about emissions of oxides of nitrogen from petrol and diesel engines - AQA - A-Level Chemistry - Question 1 - 2020 - Paper 3
Step 1
Explain how oxides of nitrogen are formed in engines.
Answer
Oxides of nitrogen are primarily formed in engines through the reaction of nitrogen from the air with oxygen during high-temperature combustion processes. This reaction occurs when temperatures exceed 1200 degrees Celsius, allowing nitrogen and oxygen to combine and produce nitrogen oxides (NO and NO₂).
Step 2
State why it is desirable to decrease emissions of oxides of nitrogen from vehicles.
Answer
It is desirable to decrease emissions of oxides of nitrogen from vehicles because these compounds contribute to the formation of acid rain, which can harm ecosystems, and to respiratory problems in humans. Reducing these emissions can lead to better air quality and environmental health.
Step 3
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Step 5
State the meaning of the term heterogeneous catalyst.
Answer
A heterogeneous catalyst is a catalyst that exists in a different phase (solid, liquid, or gas) than the reactants. For example, in a catalytic converter, the solid platinum acts as a catalyst in the gas-phase reactions of the exhaust gases.
Step 6