1 Most of the fuels used today are obtained from crude oil - Edexcel - GCSE Chemistry Combined Science - Question 1 - 2019 - Paper 1
Question 1
1 Most of the fuels used today are obtained from crude oil.
(a) Which statement about crude oil is correct?
A crude oil is a compound of different hydrocarbons
B... show full transcript
Worked Solution & Example Answer:1 Most of the fuels used today are obtained from crude oil - Edexcel - GCSE Chemistry Combined Science - Question 1 - 2019 - Paper 1
Step 1
Which statement about crude oil is correct?
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Answer
B crude oil is a mixture of hydrocarbons. This is the correct statement as crude oil consists of various types of hydrocarbons that can be separated through processes like fractional distillation.
Step 2
State a use for each of these fractions.
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Answer
Kerosene is commonly used as a fuel for jet engines, while diesel oil is primarily used in vehicles and for heating purposes.
Step 3
Choose a property. State how this property for kerosene compares with the property for diesel oil.
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Answer
Property: Boiling point. Kerosene has a lower boiling point than diesel oil, which is why it is collected higher up in the fractionating column.
Step 4
Explain, using these formulae, why butane and pentane are neighbouring members of the same homologous series.
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Answer
Butane (C4H10) and pentane (C5H12) are neighbouring members of the same homologous series because they differ by the addition of a CH2 group, which is characteristic of homologous series where each subsequent member differs by a constant unit.
Step 5
Calculate the mass of carbon in 100 g of butane.
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To find the mass of carbon in butane, we first calculate its relative formula mass: C4H10 = (4 × 12.0) + (10 × 1.00) = 58.0. The mass fraction of carbon in butane is then:
rac{4 imes 12.0}{58.0} imes 100 = 82.76 ext{ g}
Thus, the mass of carbon in 100 g of butane is 82.8 g (to three significant figures).
