This question is about the reaction scheme shown - AQA - A-Level Chemistry - Question 10 - 2022 - Paper 2
Question 10
This question is about the reaction scheme shown.
Step 1
Step 2
Step 3
Step 4
Step 5
Amine A
Amine B
Worked Solution & Example Answer:This question is about the reaction scheme shown - AQA - A-Level Chemistry - Question 10 - 2022 - Paper 2
Step 1
Step 1
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Answer
The reagents needed for step 1 are concentrated nitric acid (HNO₃) and concentrated sulfuric acid (H₂SO₄).
Step 2
Step 2
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Answer
For step 2, the reagent needed is lithium aluminum hydride (LiAlH₄) in an appropriate solvent like ether.
Step 3
Give the name of the mechanism for the reaction in step 3.
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The mechanism for the reaction in step 3 is nucleophilic addition-elimination.
Step 4
Name the reagent for step 4.
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The reagent for step 4 is chlorine (Cl₂).
Step 5
State a necessary condition for step 4.
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A necessary condition for step 4 is exposure to UV light.
Step 6
Explain why the yield of B in step 5 is less than the yield of A in step 2.
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In step 5, further substitution can occur and give other amine products, resulting in a lower yield for amine B compared to amine A, which is formed in a more straightforward reaction.
Step 7
Explain why amine B is a stronger base than amine A.
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Amine B is a stronger base than amine A due to the electron-donating effect of the alkyl group. The B aryl group enhances the availability of the lone pair electrons on the nitrogen, making it more basic compared to amine A.
