Amines and Amides

Question 1

primary aliphatic amines

Answer 1

Primary aliphatic amines can be prepared by the reaction of ammonia with halogenoalkanes and by the reduction of nitriles.

Question 2

aromatic amines

Answer 2

Aromatic amines, prepared by the reduction of nitro compounds, are used in the manufacture of dyes.

Question 3

amines =

Answer 3

weak bases = lone electron pair on nitrogen atom can accept protons

Question 4

primary aliphatic amines

Answer 4

Primary aliphatic amines act as Bronsted-Lowry bases because the
lone pair of electrons on the nitrogen is readily available for forming a
dative covalent bond with a H+
and so accepting a proton. They are
weak bases as only a low concentration of hydroxide ions is produced.

Question 5

formation of ammonium ions

Answer 5

NH3 (aq) +H2O (l) ⇌NH4+(aq)+OH-(aq)

Question 6

weak to strong base order

Answer 6

Aromatic amines < ammonia< primary amines< tertiary amines< secondary amines

Question 7

amine + acid =

Answer 7

ammonium salts

Question 8

amines

Answer 8

mine + acyl chloride or acid anhydride = amide

Naming amines:

e.g 4 carbon chain = butylamine 

Amine attached to benzene ring = phenylamine 

Question 9

what are aromatic amines

Answer 9

Aromatic amines = only when nitrogen is direcetly bonded to benzene ring

Question 10

content

Answer 10

Tertiary amines and amides do not experience hydrogen bonding

Amines can use their lone pairs to act as a nucelophile =electron pair donor

Amines convert CO2 and hydrogen sulfuide into less harmful products

Aliphatic amines –> ammonia –> aromatic amines = decreasing levels of pH

The more avaliable a lone pair is the stronger the base (more likely to accept a proton)

Aliphatic amine: An amine in which nitrogen is bonded only to alkyl groups

Question 11

nucelophilic addition elimination

Answer 11

In nucelophilic addition elimination reactions the amine acts as a nucelophile

Chance of nucelophilic subsitution reactions occuring happens when excess halogenoalkane is used

Question 12

cattionic surfaces

Answer 12

Quaternary ammonium ion salts can be used as cationic sufactants (soaps)

-surfactants = polar end and non-polar end

Question 13

bonding in amines

Answer 13

-H2N – CH3 = methylamine (primary amine)

-hydrogen bonding is present between the molecules of methylamine

Question 14

aromatic amines

Answer 14

-in aromatic amines the nitrogen lone pair is partially delocalised into the benzene ring, lowering base strength

Question 15

naming amines

Answer 15

Amines = count the number of carbons directly attached to the nitrogen atom

-quaternary ammonium salts are not amines

Question 16

phenylammonium chloride production

Answer 16

Phenylamine + HCl –> phenylammonium chloride (Water soluble ionic salt)

Question 17

6 strong bases

Answer 17

-LiOH = lithium hydroxide

-NaOH = sodium hydroxide

-KOH = potassium hydroxide

-Ca(OH)2 = calcium hydroxide

-Sr(OH)2 = strontium hydroxide

-Ba(OH)2 = barium hydroxide

Question 18

strength of bases

Answer 18

Dimethylamine is a stronger base than methylamine as it is secondary amine. Has a greater electron density on the nitrogen lone pair and therefore a greater ability to accept a proton (H+)

Question 19

comparing strengths

Answer 19

-alkyl group release electrons away from alkyl group and towards the nitrogen atom (positive inductive effect)

-this inductive effect increases the electron density on the nitrogen atom (better electron pair donor_

-primary amine is stronger than NH3

-secondary amine is stronger than primary amine

-teritary amine is not a stronger base (less soluble in water)

Question 20

teritary amines

Answer 20

-not stronger bases than secondary amines bc they are less soluble in wtaer

-teritary amines don’t have N-H bonds

Question 21

Whats stronger propylamine or phenylamine:

Answer 21

Whats stronger propylamine or phenylamine:

-propylamine = lone pair on phenylamine is partially delocalised into the benzene ring

-propylamine has a greater eletron density on the nitrogen lone pair

-propylamine has a greater ability to accept H+

Question 22

more alkyl groups

Answer 22

The more alkly groups attached to the amine the more strongly proton is attracted to the amine. The strength of bases is determined by how readily it will accept a proton

Question 23

nucleophilic subsitution

Answer 23

Nucelophilic subsitution:

-haloalkane + ammonia = primary amine and ammonium salt

Question 24

reduction of nitriles

Answer 24

-reducing nitriles via hydrogenation can produce amines

-requires LiAlH4 (reducing agent)

-R-C=N + reducing agent) –> R-CH2-NH2

Question 25

production of aromatic amines

Answer 25

Production of aromatic amines:

-produced from the reduction of nitrobenzene using HCl and a tin catalyst

Question 26

CH3Br –> C2H3N

Answer 26

KCN

alcohol

Question 27

C2H3N –> C2H7N

nitrile –> amine

Answer 27

H2
Ni catalyst