Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Crude Oil
106 practice questions
Topics covered
Practice questions
41–50 of 106
Question 41
2 marks · Easy
Answer and see the solution →Incomplete combustion of hydrocarbons can take place when there is insufficient oxygen available. Explain, using your knowledge of combustion, why incomplete combustion of hydrocarbons does not produce as much energy as complete combustion.
Question 42
3 marks · Easy
Answer and see the solution →The table below shows approximate boiling points for some fractions separated from crude oil using fractional distillation. Complete the table by filling in the missing fraction names.
Fraction Approximate Boiling Point (C) Refinery gases <40 ___ 40–180 Kerosene 180–260 ___ >350 Question 43
1 mark · Easy
Answer and see the solution →State one product, other than carbon dioxide, formed during the incomplete combustion of a hydrocarbon fuel.
Question 44
3 marks · Easy
Answer and see the solution →The diagram shows a simplified fractional distillation column for crude oil. The temperature at three different positions is marked.
Fractionating column (simplified, labelled) The temperature at the bottom is 370 C, in the middle is 220 C, and at the top is 40 C.
(a)[1 mark]State what happens to the hydrocarbons as their vapours rise up the column.
(b)[1 mark]Name the fraction collected at the top of the column.
(c)[1 mark]Explain why some hydrocarbons are collected at the bottom instead of higher up.
Question 45
2 marks · Easy
Answer and see the solution →Crude oil is separated in a fractionating column. A crude oil sample produces 100 kg of gasoline, 60 kg of kerosene, and 30 kg of diesel oil after fractional distillation. The total mass of these fractions is collected.
Calculate the percentage by mass of the gasoline fraction in the sample. Give your answer to 1 decimal place.
Question 46
2 marks · Easy
Answer and see the solution →A hydrocarbon burns in exactly 20 g of oxygen during complete combustion. Calculate the mass of carbon dioxide produced if all the oxygen is converted into carbon dioxide. (Assume all atoms from oxygen go into making carbon dioxide; ignore water formation for this calculation. Relative atomic masses: C = 12, O = 16)
Question 47
2 marks · Normal
Answer and see the solution →State the name of the process used to separate crude oil into useful fractions and give one reason why crude oil must be separated in this way.
Question 48
4 marks · Normal
Answer and see the solution →This question is about combustion of hydrocarbons.
(a)[1 mark]Write the word equation for the complete combustion of propane.
(b)[1 mark]State the two main products formed during complete combustion of a hydrocarbon.
(c)[2 marks]Explain, using your knowledge of incomplete combustion, why burning a hydrocarbon in a limited supply of air may produce a dangerous gas.
Question 49
3 marks · Normal
Answer and see the solution →Explain why burning hydrocarbons in a poorly ventilated room can lead to serious health risks. In your answer, refer to the products formed during incomplete combustion.
Question 50
4 marks · Normal
Answer and see the solution →The table below shows information about some fractions obtained from crude oil.
Fractions from crude oil Fraction Approximate Boiling Point (°C) Main Use Refinery gas < 40 Bottled gas Gasoline 40–100 Fuel for cars Diesel oil 250–350 Fuel for lorries Bitumen > 350 Road surfacing (a)[1 mark]Identify the fraction with the lowest boiling point and state its main use.
(b)[2 marks]Which fraction is most likely to contain the largest hydrocarbon molecules? Explain your answer using data from the table.
(c)[1 mark]Suggest why bitumen is not used as a fuel.