28 - Amines

Question 1

How can amines be formed?

Answer 1

Nucleophilic substitution of halogenoalkane with ammonia
Reduction of nitriles

Question 2

What are aromatic amines used for?

Answer 2

Manufacture of dyes

Question 3

Describe the difference in base strength between ammonia, primary aliphatic, and primary aromatic amines.

Answer 3

Primary amines > ammonia > phenylamines

Question 4

How can a high yield of a quaternary salt be produced?

Answer 4

Reaction of an excess halogenoalkane with ammonia.

Question 5

What can quaternary ammonium salts be used for?

Answer 5

Cationic surfacants

Question 6

Justify the statement that it is better to prepare primary amines from nitriles rather than from halogenoalkanes. (2)

Answer 6

Halogenoalkanes produce a mix of products, whereas nitriles produce only a single product.

Question 7

Explain why 3-aminopentane is a stronger base than ammonia. (2)

Answer 7

Lone pair on N more available to accept proton
Because of inductive effect.

Question 8

What effect does delocalisation does on the availability of the N lone pair?

Answer 8

Decreases availability