27 - Amines, Amino acids and Polymers

Question 1

What are amines

Answer 1

derivatives of ammonia

one of more of the h’s on NH3 has been replaced by an organic group

Question 2

aliphatic amine

Answer 2

the N atom is attached to atleast one straight or branched carbon chain

Question 3

aromatic amine

Answer 3

the N atom is attached to an aromatic ring

Question 4

how do you determine if a amine is primary / secondary / tertiary

Answer 4

depends on the number of alkyl groups attached to the N atom

Question 5

why do amines act as bases

Answer 5

the N atom on ammonia has a lone pair of electrons that can accept protons

Question 6

amine + dilute acid

Answer 6

–> ammonium salt

Question 7

why can ammonia act as a nucleophile in a substitution reaction with a haloalkane

Answer 7

has a lone pair of e’s

Question 8

reagents needed for

nucelophilic subs of ammonia with haloalkane

Answer 8

haloalkane
excess ammonia
in ethanol solvent

Question 9

why is a ethanol solvent used in

nucelophilic subs of ammonia with haloalkane

Answer 9

prevents substitution of haloalkane by water to produce alcohols

Question 10

why is ammonia used

nucelophilic subs of ammonia with haloalkane

Answer 10

reduces further substitution

of primary into seco into tert

Question 11

consitions needed for

nucelophilic subs of ammonia with haloalkane

Answer 11

heat

Question 12

conditions needed for

prepartaion of aromatic amines

Answer 12

reflux

Question 13

reagents needed for

preparation of aromatic amines

Answer 13

tin (Sn)

conc. HCl

Question 14

what is the reaction needed to form an aromatic amine and what type of reaction

Answer 14

nitrobenzene + 6reducing agent –> aromatic amine + 2H2O

reduction reaction

Question 15

what functional groups do amino acids have

Answer 15

carboxylic acid

amine

Question 16

what is an alpha amino acid

Answer 16

the amine and carboxylic functional groups are attached to the same carbon

Question 17

what is the general formula of alpha amino acid

Answer 17

RCH(NH2)COOH

Question 18

beta amino acid

Answer 18

amine is connected to the 3rd carbon

Question 19

gamma amino acid

Answer 19

amine connected to 4th carbon

Question 20

reactions of amine groups in amino acids

Answer 20

amino acid + acid –> salt

Question 21

reactions of carboxylic acid groups in amino acids

Answer 21

amino acid + aq alkali –> salt + h2o

amino acid + alcohol –> ester + h20

Question 22

reagents and conditions of esterfication of amino acids

Answer 22

cond = heat 
reagents = amino acid + conc. H2SO4 + excess alcohol

Question 23

what is a zwitter ion

Answer 23

formed when the amine froup accepts a proton from the carboxylix group - forming an ion with both positive and negative charge

have no overall charge - cancels out

Question 24

what is the isoelectric point

Answer 24

the pH which the zwitterion is formed

each amino acid has a unique isoelectric point

Question 25

what happens if the amino acid is put in a solution with a pH greater than its isoelectric point

Answer 25

the AA behaves as an acid - loses a proton

Question 26

what happens if the amino acid is put in a solution with a pH lower than its isoelectric point

Answer 26

the AA behaves as an base - gains a proton

Question 27

optical isomerism

Answer 27

sterioisomers that are non-superimposable mirror images of each other = enantiomers

Question 28

sterioisomerism

Answer 28

compounds with the same structural formula but different arrangement of atoms in space

Question 29

chiral centre

Answer 29

c atom attached to 4 different atoms

Question 30

what is condensation polymerisation

Answer 30

the joining of monomers with loss of a small molecule - usually water / hcl

Question 31

condensation polymerisation to form polyesters

Answer 31

monomers are joined by ester linkages can be made from: - 1 monomer containing both a CA and alcohol group - 2 monomers - 1 with both CA - 1 with both OH

Question 32

dimerisation

Answer 32

2 molecules of the same compound react together

Question 33

how does a polyester formed from its monomer

Answer 33

the CA group in 1 molecule reacts with the OH group in another to form an ester bond and h20

Question 34

polymerisation of 1 monomer to form polester

Answer 34

(n-1)h20

Question 35

polymerisation of 2 monomer to form polester

Answer 35

(2n-1)h20

Question 36

condensation polymerisation to form polyamides

Answer 36

monomers joined by amide linkages - 1 monomer with both CA (or acyl chloride) and amines - 2 monomers

Question 37

amino acid undergo condensation polymerisation to form

Answer 37

polypeptides - polyamides

Question 38

how does a polamide formed from its monomer

Answer 38

CA group of one molecule reacts with amine group in another to form amide link

Question 39

why are amides soluble

Answer 39

o in the OH group has a lone pair of electrons that can hydrogen bond with water molcules N in amine group...

Question 40

what is needed to hydrolyse polyamides and polyesters

Answer 40

hot aquesous alkali | hot aquoues acid