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5 (c) Some fractions from crude oil contain large hydrocarbon molecules - AQA - GCSE Chemistry - Question 5 - 2015 - Paper 1
Question 5
5 (c) Some fractions from crude oil contain large hydrocarbon molecules. 5 (c) (i) Hydrocarbon molecules, such as decane, can be cracked to produce smaller, more us... show full transcript
Worked Solution & Example Answer:5 (c) Some fractions from crude oil contain large hydrocarbon molecules - AQA - GCSE Chemistry - Question 5 - 2015 - Paper 1
Step 1
Step 2
Pentene is used to produce poly(pentene). Complete the equation and the displayed structure of poly(pentene).
Answer
The equation for the production of poly(pentene) can be presented as:
The displayed structure of poly(pentene) consists of long chains of carbon atoms joined by single bonds, with hydrogen atoms filling the remaining valencies.
Step 3
Step 4
Describe how crude oil is separated into fractions.
Answer
Crude oil is separated into fractions through a process known as fractional distillation. In this process, the crude oil is heated in a distillation column. The heat causes the hydrocarbons to evaporate into vapors, which rise through the column. As the temperature decreases higher up the column, different fractions condense back into liquids at their respective boiling points. This allows for the collection of various hydrocarbons based on their boiling points.
Step 5
Suggest how the use of a suspension of limestone decreases one of the environmental impacts that the waste gases would cause.
Answer
When waste gases containing sulfur dioxide are passed through a suspension of limestone (calcium carbonate), the limestone reacts with the sulfur dioxide to form calcium sulfate, a less harmful substance. This reaction helps to mitigate the acid rain caused by sulfur dioxide emissions, thus reducing its environmental impact.