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 B is formed in step 5.
1.0.1 State the reagents needed for step 1 a... show full transcript
Worked Solution & Example Answer:This question is about the reaction scheme shown - AQA - A-Level Chemistry - Question 10 - 2022 - Paper 2
Step 1
State the reagents needed for step 1 and the reagents needed for step 2.
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Answer
Step 1 requires concentrated nitric acid (HNO₃) and concentrated sulfuric acid (H₂SO₄) as the reagents. For step 2, the reagents needed are steps 1 and 2, including an amine or reductive agent.
Step 2
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 3
Name the reagent for step 4.
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The reagent needed for step 4 is chlorine (Cl₂).
Step 4
State a necessary condition for step 4.
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A necessary condition for step 4 is the presence of ultraviolet light (UV).
Step 5
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 lead to the formation of other amine products, which decreases the yield of amine B compared to the yield of amine A in step 2 where only one product is formed.
Step 6
Explain why amine B is a stronger base than amine A.
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Amine B has an alkyl group that exerts an electron-donating or positive inductive effect, increasing the availability of the lone pair of electrons for protonation. In contrast, amine A has less electron density available due to the differences in substitution.
