Topic 22: Amines

Question 1

What are aliaphatic amines

Answer 1

Amines with normal alkyl groups

Question 2

What do cationic surfactants consist of

Answer 2

Quarternary ammonium salt and an anion

Question 3

Cationic surfactant uses

Answer 3

Fabric cleaners
Hair products

Question 4

Order of strength of base (Amines)

Answer 4

Weakest: Primary aromatic amine
Middle: Ammonia
Strongest: Primary aliphatic amines

Question 5

Why are primary aliphatic amines the strongest bases?

Answer 5

Positive inductive effect
Increases electron density in lone pair
Lone pair is more avaliable

Question 6

Why are primary aromatic amines weak bases?

Answer 6

Electron density is drawn into benzenes delocalised electron network
This decreases electron density around lone pair

Question 7

Two reactions to form amines

Answer 7

Nuclophilic substitution of ammonia
Heating a halogenoalkane with excess ammonia
(mixture of primary, secondary, tertiary and quaternary amines)

Reduce a nitrile to make primary amine
1. LiAlH4 in dry ether followed by dilute acid (expensive)
or
2. Hydrogen gas with a metal catalyst (nickel) at high temperature and pressure (catalytic hydrogenation

Question 8

Conditions for further substitution ( Nucleophilic substitution of ammonia)

Answer 8

Excess halogenoalkane