This question is about cycloalkenes - AQA - GCSE Chemistry - Question 6 - 2021 - Paper 2
Question 6
This question is about cycloalkenes.
Cycloalkenes are ring-shaped hydrocarbon molecules containing a double carbon-carbon bond.
Cycloalkenes react in a similar way... show full transcript
Worked Solution & Example Answer:This question is about cycloalkenes - AQA - GCSE Chemistry - Question 6 - 2021 - Paper 2
Step 1
Describe a test for the double carbon-carbon bond in cycloalkene molecules.
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Answer
The test for a double carbon-carbon bond in cycloalkenes involves adding bromine water to the sample. If a double bond is present, the bromine water will change from brown/orange to colourless.
Step 2
Determine the general formula for cycloalkenes.
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Answer
The general formula for cycloalkenes can be determined to be CₙH₂ₙ, where n is the number of carbon atoms.
Step 3
Complete Figure 7 to show the displayed structural formula of C6H10Cl2.
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Answer
The displayed structural formula of C6H10Cl2 includes two chlorine atoms bonded to the cyclohexene structure, specifically at carbon atoms 1 and 2, or other positions depending on the isomer.
Step 4
Calculate the percentage by mass of chlorine in a molecule of C6H10Cl2.
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Answer
The molar mass of C6H10Cl2 can be calculated as follows:
Carbon: 6 × 12 = 72
Hydrogen: 10 × 1 = 10
Chlorine: 2 × 35.5 = 71
Thus, total molar mass = 72 + 10 + 71 = 153 g/mol.
