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Crude oil is fractionally distilled to produce fractions - Edexcel - GCSE Chemistry - Question 5 - 2017 - Paper 1
Question 5
Crude oil is fractionally distilled to produce fractions. These fractions have many uses. Complete the sentence by putting a cross (✓) in the box next to your answe... show full transcript
Worked Solution & Example Answer:Crude oil is fractionally distilled to produce fractions - Edexcel - GCSE Chemistry - Question 5 - 2017 - Paper 1
Step 1
Complete the sentence by putting a cross (✓) in the box next to your answer.
Answer
The fraction least likely to be used as a fuel is A bitumen. This is because bitumen is a heavy fraction with a high boiling point, making it less suitable for combustion compared to the other listed fuels.
Step 2
Describe what is meant by cracking.
Answer
Cracking is a chemical process used in the petroleum industry where larger hydrocarbon molecules are broken down into smaller, more useful ones, often in the presence of heat and a catalyst. This process converts heavier fractions into lighter hydrocarbons such as gasoline or diesel.
Step 3
Step 4
Use your knowledge of hydrogen and petrol to explain the advantages and disadvantages of using hydrogen rather than petrol as the fuel in cars.
Answer
Advantages of using hydrogen as a fuel include:
- Cleaner burning: Hydrogen combustion produces only water vapor as a byproduct, reducing air pollution compared to petrol.
- Renewable potential: Hydrogen can be produced from renewable sources, lowering dependency on fossil fuels.
Disadvantages include:
- Hydrogen production: The current methods to produce hydrogen can be energy-intensive and may still rely on fossil fuels.
- Infrastructure: There is a lack of widespread hydrogen fueling stations, making it less practical than petrol for everyday use.
- Energy density: Hydrogen has a lower energy density by volume compared to petrol, requiring larger storage tanks.