CL 27- amines, amino acids and polymers

Question 1

how does an amine act as a base?

Answer 1

the lone pair on N can accept a proton

Question 2

ethanamine + HCl

equation and name of product

Answer 2

• CH₃CH₂NH₂ + HCl –> CH₃CH₂NH₃Cl
• ethylammonium chloride (a salt)

Question 3

preparation of a primary amine

reactants and reasons

Answer 3

• chloroalkane
• react with excess ammonia (to prevent further substitution)
• use ethanol as a solvent (water will compete with ammonia to replace halogen so can’t be used)

Question 4

preparation of ethanamine from chloroethane

equation

Answer 4

(ethanol on arrow)
CH₃CH₂Cl + 2NH₃ –> CH₃CH₂NH₂ + NH₄Cl

Question 5

formation of a secondary amine

Answer 5

• chloroalkane
• primary amine

Question 6

equation for the formation of diethanamine

Answer 6

CH₃CH₂Cl + 2CH₃CH₂NH₂ –> (CH₃CH₂)₂NH + CH₃CH₂NH₃Cl

Question 7

formation of aromatic amines

steps

Answer 7

1. nitration of benzene ring (conc HNO₃ and conc H₂SO₄)
2. reduction of nitrobenzene- add reducing agent Sn/conc HCl

Question 8

formation of phenylamine

equation

Answer 8

nitrobenzene + 6[H] –> phenylamine + 2H₂O

Question 9

more mechanisms didn’t know where to put them

aliphatic amine extended C chain steps

Answer 9

1. add KCN to a chloroalkane to form a nitrile (nucleophilic substitution)
2. turn into an amine by adding H₂/Ni to saturate the triple CN bond

Question 10

nitrile to carboxylic acid

reagents

Answer 10

• heat with dilute acid
• example of hydrolysis

Question 11

propanenitrile to propanoic acid

equation

Answer 11

CH₃CH₂CN + 2H₂O + H⁺ –> CH₃CH₂COOH + NH₄⁺

Question 12

refresher

stereoisomer

definition

Answer 12

same structural formula but different arrangement of atoms in space

Question 13

conditions for optical isomers

Answer 13

• must contain a chiral carbon ( 4 different groups joined to the same C)
• mirror images (easy way to draw)
• make sure when drawing 3D, there’s an obvious 107 degree angle, and 1 dashed 1 filled wedge