This question is about hydrocarbons - AQA - GCSE Chemistry - Question 3 - 2020 - Paper 2
Question 3
This question is about hydrocarbons.
Hexane and hexene are hydrocarbons containing six carbon atoms in each molecule.
Hexane is an alkane and hexene is an alkene.
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Worked Solution & Example Answer:This question is about hydrocarbons - AQA - GCSE Chemistry - Question 3 - 2020 - Paper 2
Step 1
Draw one line from each hydrocarbon to the formula of that hydrocarbon.
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Answer
Hexane corresponding to C₆H₁₄ and Hexene corresponding to C₆H₁₈.
Step 2
What would be observed when bromine water is added to hexane and to hexene?
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Answer
Hexane will remain orange when bromine water is added, indicating no reaction.
Hexene will become colourless, indicating a reaction due to the presence of a double bond.
Step 3
Compare ethane with ethene.
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Answer
Structure and Bonding
Both ethane and ethene are hydrocarbons; however, ethane has a single bond between carbon atoms while ethene has a double bond. Additionally, ethane contains six hydrogen atoms, while ethene contains four.
Reactions
Both react with oxygen in complete combustion to produce water and carbon dioxide. But ethene is more reactive than ethane, allowing it to react with bromine water, causing a color change, while ethane cannot. Both can also undergo incomplete combustion.
