Amines

Question 1

Explain why amines are able to act as Bronsted-Lowry bases.

Answer 1

• Proton acceptor
• Lone pair of electrons in N is donated to H⁺
• Forming a dative covalent bond

Question 2

BRONSTED-LOWRY BASE

Answer 2

Proton acceptor

Question 3

Amines as Bases

amine + acid

Answer 3

amine + acid → ammonium salt

RNH₂ + HCl → RNH₃⁺Cl⁻

Question 4

Preparation of Aliphatic Amines

halogenoalkane + excess ammonia

Answer 4

halogenoalkane + excess ammonia → amine + amonium salt
RCl + 2NH₃ → RNH₂ + NH₄⁺Cl⁻
Excess ethanolic ammonia

Question 5

Reduction of Nitrobenzene

Answer 5

C₆H₅NO₂ + 6[H] → C₆H₅NH₂ + 2H₂O

Sn catalyst/conc. HCl/Reflux

Question 6

Diazotisation: Reagents and Conditions

Answer 6

Reagents: NaNO₂/HNO₂/HCl
Conditions: Temp below 10°C

Question 7

Diazotisation: Equation

Answer 7

C₆H₅NH₂ + HCl + HNO₂ → C₆H₅N⁺≡NCl⁻ + 2H₂O

Question 8

Coupling with a Phenol: Reagents and Conditions

Answer 8

Reagents: NaOH
Conditions: Alkali

Question 9

Coupling with a Phenol: Equation

Answer 9

C₆H₅N⁺≡NCl⁻ + C₆H₅OH → C₆H₅N=NC₆H₅OH + HCl