Suggest a suitable temperature for the furnace in Figure 1 - AQA - GCSE Chemistry - Question 1 - 2019 - Paper 2
Question 1
Suggest a suitable temperature for the furnace in Figure 1.
______ °C
Explain why diesel oil collects above heavy fuel oil but below kerosene in the fractionating ... show full transcript
Worked Solution & Example Answer:Suggest a suitable temperature for the furnace in Figure 1 - AQA - GCSE Chemistry - Question 1 - 2019 - Paper 2
Step 1
Suggest a suitable temperature for the furnace in Figure 1.
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Answer
A suitable temperature for the furnace is between 400 °C and 500 °C inclusive.
Step 2
Explain why diesel oil collects above heavy fuel oil but below kerosene in the fractionating column.
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Answer
Diesel oil has a higher boiling point than kerosene, but a lower boiling point compared to heavy fuel oil. This range allows diesel oil to be collected between these two fractions in the fractionating column.
Step 3
Suggest two reasons why bitumen is not used as a fuel.
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Answer
Bitumen is too viscous, making it difficult to flow.
Bitumen is not very flammable, which limits its usability as a fuel.
Step 4
Which of the following compounds is an alkane?
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Answer
The compound that is an alkane is C₁₄H₁₄.
Step 5
Describe the conditions needed to crack hydrocarbon molecules from the diesel oil fraction.
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Answer
The conditions needed to crack hydrocarbon molecules include high temperature, typically above 320 °C, and the presence of a catalyst such as steam or alumina.
Step 6
Explain why large hydrocarbon molecules in the diesel oil fraction are cracked to produce smaller hydrocarbon molecules.
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Answer
Larger hydrocarbon molecules are cracked to meet the greater demand for smaller molecules, which are more useful and are desired for applications such as fuels or to produce alkenes.
Step 7
Complete the equation for the cracking of C₁₅H₃₂.
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Answer
The complete equation for cracking is: C₁₅H₃₂ → C₁₂H₂₆ + C₃H₆.
