Crude oil is a mixture of hydrocarbons - AQA - GCSE Chemistry Combined Science - Question 1 - 2018 - Paper 2
Question 1
Crude oil is a mixture of hydrocarbons.
The hydrocarbons in crude oil are separated into fractions by fractional distillation.
Figure 1 shows a fractional distilla... show full transcript
Worked Solution & Example Answer:Crude oil is a mixture of hydrocarbons - AQA - GCSE Chemistry Combined Science - Question 1 - 2018 - Paper 2
Step 1
Complete the sentence.
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Answer
Crude oil vapour passes up the column and condenses into different fractions at different levels.
Step 2
Why do the fractions separate?
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Answer
The fractions separate because they have different boiling points.
Step 3
Name the alkane.
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Answer
The alkane is propane.
Step 4
What is the general formula for alkanes?
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Answer
The general formula for alkanes is CₙH₂ₙ₊₂.
Step 5
Balance the equation for methane burning.
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Answer
The balanced equation is: CH₄ + 2 O₂ → CO₂ + 2 H₂O.
Step 6
Which reagent is used to test for alkenes?
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Answer
The reagent used to test for alkenes is bromine water.
Step 7
Why are life cycle assessments (LCA) done?
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Answer
Life cycle assessments (LCA) are done to assess the environmental impact of the stages in the life of a product.
Step 8
Compare the two methods for the disposal of biodegradable plastic bags.
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Answer
Burning 10,000 bags produces 10 kg of carbon dioxide, while putting 10,000 bags in landfill produces 5 kg of carbon dioxide. In terms of solid residue, burning produces 0.50 kg while landfill produces 0.70 kg of solid. Additionally, burning produces less sulfur dioxide (0.20 kg) compared to landfill (0.30 kg).
