amines DONT UNDERSTAND NEED TO DO WITH MIKE

Question 1

explain why butyl amine is able to act as a base

write an equation for the reaction of butylamine with aqueous HCl

Answer 1

lone pair on nitrogen is able to accept a proton

C4H11NH2 + HCl —> C4H11NH3+Cl-

Question 2

why is phenyl amine one of the weakest bases

Answer 2

• lone pair on Nitrogen is less available
• because the lone pair of electrons on the N are with drawn as they overlap with the delocalised electrons in the benzene ring

Question 3

why are alkyl amines stronger bases

Answer 3

• lone pair on nitrogen is more available/ lone pair on N accepts H+ better
• because alkyl groups release electrons (inductive effect)

Question 4

give the reagents and conditions of the 2 methods to produce an amine

Answer 4

halogenoalkane - halogenoalkane with an excess of ammonia in a sealed tube

nitrile - reduction of nitrile using LiAlH4 (lithium aluminium hydride dissolved in ether) - reduction of nitrile

Question 5

How do you make a primary amine from reducing a nitrile (HINT: 2 step reaction)

Answer 5

1. halogenoalkane reacts with cyanide ion in aqueous ethanol (nucleophilic substitution)

RBr + CN- —–> RCN + :Br-

2. nitriles are reduced to primary amines with a Ni/H2 catalyst

R - CN + 2H2 —> RCH2NH2

only a primary amine is formed in this reaction

Question 6

what is the 2 step reaction used to produce phenyl amine from nitrobenzene

Answer 6

1. mix nitrobenzene with tin (Sn) and conc HCl leave at room temp
   it is a reduction reaction
2. add NaOH to remove H+ from phenylammonium ion

Question 7

give 3 uses of amines

Answer 7

• dyes
• drugs
• in polymers (e.g: nylon)

Question 8

what are quaternary ammonium compounds used for

Answer 8

in the manufacturing of conditioner for hair and fabric

they are called cationic surfactants