Amines and amidesEdexcel A-Level Chemistry: Mind map

Exam questions on Amines and amides

1. Butylamine, CH₃(CH₂)₃NH₂, is a primary aliphatic amine. It dissolves in water to give an alkaline solution and it neutralises dilute hydrochloric acid.
   A student adds butylamine dropwise, and then in excess, to aqueous copper(II) sulfate. Describe what is observed and explain the change seen in excess.2 marks
2. A student compares the strengths of three bases at 298 K using their pKb values. A lower pKb means a stronger base. Ammonia, NH₃, has pKb = 4.75, butylamine, CH₃(CH₂)₃NH₂, has pKb = 3.39 and phenylamine, C₆H₅NH₂, has pKb = 9.13.
   Explain why butylamine is a stronger base than ammonia.2 marks
3. Primary aliphatic amines can be prepared from halogenoalkanes or by reduction of nitriles. Butylamine, CH₃(CH₂)₃NH₂, can be made from 1-bromobutane, and it can also be made by reducing the nitrile butanenitrile, CH₃CH₂CH₂CN.
   State the reagent and conditions for converting 1-bromobutane into butylamine, and explain why a large excess of the reagent is used.3 marks