carboxylic acids/ esters/ polymers

Question 1

functional group- carboxylic acid

Answer 1

COOH

Question 2

general formula - carboxylic acid

Answer 2

CnH2n+1COOH

Question 3

how to make carboxylic acids

Answer 3

made by oxidation of alcohols
eg ethanol oxidised to ethanoic acid

Question 4

ethanol oxidation

Answer 4

make ethanoic acid
sped up by warming with oxidising agent
eg acidified potassium dichromate
orange to green

Question 5

chemical properties - carboxylic acids

Answer 5

weak acids
react with metals like normal acids but less vigorously

Question 6

ethanoic acid

Answer 6

(vinegar)
- weak acid
- reacts with metal to make to make hydrogen and metal salt

Question 7

salts from carboxylic acids

Answer 7

methanoic > methanoate salt
ethanoic > ethanoate salt
propanoic > propanoate salt
butanoic > butanoate salt

Question 8

esters reaction

Answer 8

carboxylic acid + alcohols > ester + water
(reversible)
esterification reaction
condensation (water is made)
catalysed by a strong acid eg sulphuric

Question 9

ester functional group

Answer 9

O
||
O - C

Question 10

how to bond acid and alcohols (diagram)

Answer 10

remove water and bond together
H O H H
| || | |
H - C - C H - O - C - C - H
| | | |
H O- H H H

Question 11

naming esters

Answer 11

number of carbons in alcohol + yl eg propyl
number of carbons in acid + anoate eg ethanoate

eg propylethanoate

Question 12

polymers

Answer 12

very long molecules made by joined repeated smaller molecules
exist in nature or are synthetic

Question 13

polyethene uses

Answer 13

plastic bags
bottles

Question 14

PVC used

Answer 14

water pipes
insulation for electricity cables

Question 15

polypropene uses

Answer 15

crates and ropes

Question 16

polystyrene

Answer 16

packaging

Question 17

teflon

Answer 17

non-stick pans

Question 18

nylon/ terylene uses

Answer 18

clothes

Question 19

monomer

Answer 19

molecular units that join with similar units to form a polymer

Question 20

polymerisation

Answer 20

reacting monomer molecules together in a chemical reaction to form polymer chains

Question 21

two polymerisation types

Answer 21

addition
condensation

Question 22

addition polymerisation

Answer 22

eg polymerisation of ethene to form poly(ethene)
double bond opens into a single bond and is joined with other monomers
show repeating of the polymer and multiple monomers using ‘n’

Question 23

addition polymerisation example

Answer 23

H H
| | | |
nC==C > -[-C-C-]-n
| | | |
H H
have to have n to show repeating polymer and multiple monomers
use long - outside square brackets

Question 24

define addition polymerisation

Answer 24

many monomers bond via rearrangement of bonds without the loss of atoms or molecules

Question 25

condensation polymerisation

Answer 25

eg polyester
two different monomers join
- double bonds don’t break
- join by eliminating small molecules
- an alcohol with two OH (diol) and a carboxylic acid with two COOH (dioc acid) are the monomers
- makes n(water) also

Question 26

disposing of polymers

Answer 26

• incineration
• recycling
• landfill

Question 27

disposing polymers - incineration

Answer 27

• expensive to buy furnace + burn
• releases toxins and pollutants
• pollution affects lung health, noise, traffic

Question 28

disposing polymers - recycling

Answer 28

• requires energy (expensive)
• melting releases CO2 - requires energy which uses fossil fuels to make
• takes up space - complicated due to lack of education

Question 29

disposing polymers - landfill

Answer 29

• expensive to dig hole and get line
• releases harmful chemicals and toxic run off
• ugly/ smelly - takes up space that has to be cleared