20 10 This question is about the amines butylamine, C4H9NH2 , and phenylamine, C6H5NH2 . The reaction scheme shows some reactions of butylamine, a primary amine. CH3CH2CONHC4H9 C4H9NH2 CH3CH2Br CuSO4(aq) [Cu(C4H9NH2)4]2+ solution of pH > 7 H2O Reaction 1 Reaction 2 Reaction 4 Reaction 3 C4H9NH(CH2 CH3) (a) (i) Write the equation for Reaction 1 to show why the pH of the solution is greater than 7. State symbols are not required. (1) (ii) Explain why phenylamine is a weaker base than butylamine. (3) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (b) Give the name and structural formula of the compound needed to react with butylamine in Reaction 2. (2) Name ................................................................................................................................................................................................................................................................... Structural formula ................................................................................................................................................................................................................................. Turn over 21 (c) What is seen when excess butylamine is used in Reaction 3? (1) A blue solution B blue precipitate C yellow solution D yellow precipitate (d) (i) What is the type and mechanism of the reaction in Reaction 4? (1) A electrophilic addition B electrophilic substitution C nucleophilic addition D nucleophilic substitution (ii) Complete the diagram to show the mechanism for Reaction 4. Include curly arrows, and relevant lone pairs and dipoles. (4) H3C H H C H CH3 Br C H2 C H2 C H2 H N (Total for Question 10 = 12 marks)