Organic Chemistry - SPEC

Question 1

how are polymers made and what is this process called

Answer 1

made by linking together large numbers of monomers

addition polymerisation

Question 2

how is each monomer connected within a polymer

Answer 2

with covalent bonds

Question 3

what conditions do polymerisation reactions need

Answer 3

• high pressures
• the use of a catalyst

Question 4

what are synthetic polymers

Answer 4

those that are manufactured such as polystyrene and nylon

Question 5

how to change a polymer into a polymer (for a drawing)

Answer 5

remove the two extending single bonds and create a double bond instead

Question 6

why are polymers a problem for the environment

Answer 6

they have strong C-C bonds which makes them unreactive and chemically inert so they don’t easily biodegrade

Question 7

what are the options for disposing of polymers

Answer 7

• landfill
• incineration
• recycling

Question 8

why is landfill not a good option for disposing of polymers

Answer 8

this takes up valuable land because site quickly fill up

Question 9

why is incineration not a good option for disposing of unwanted polymers

Answer 9

• they release the greenhouse gas carbon dioxide
• polymers that contain chlorine release hydrogen chloride gas when burned
• if incinerated with incomplete combustion then carbon monoxide is produced

Question 10

what are the problems with recycling unwanted polymers

Answer 10

different polymers must be separated from each other which is a difficult and expensive process

Question 11

when are condensation polymers formed

Answer 11

when two different monomers are linked together with the removal of a small molecule - usually water

Question 12

what is a key difference between addition polymerisation and condensation polymerisation

Answer 12

addition polymerisation forms the polymer molecule only

WHEREAS

condensation polymerisation forms the polymer molecule (polyester) and one water molecule per link

Question 13

WHAT ARE THE REACTANTS AND PRODUCTS OF CONDENSATION POLYMERISATION

Answer 13

REACTANTS = dicarboxylic acid, diol
products = polyester, water

Question 14

what is a dicarboxylic acid monomer

Answer 14

a carboxylic acid with a -COOH group at BOTH ends

Question 15

what is a diol

Answer 15

an alcohol with an -OH group on BOTH ends

Question 16

how do the diols and dicarboxylic acids react with each other to form a polymer

Answer 16

Each -COOH group reacts with another -OH group on another monomer

this creates a long chain of alternating monomers

Question 17

how is water formed in condensation polymerisation

Answer 17

For every ester linkage formed, one molecule of water is formed from the combination of a -H and an -OH group

Question 18

give one example of a dicarboxylic acid

Answer 18

ethanedioic acid

-dioic

Question 19

give one example of a diol

Answer 19

ethanediol

• diol

Question 20

what do each of the atoms come from that form water in condensation polymerisation

Answer 20

The OH comes from the -COOH groups of the dicarboxylic acid
The H comes from the -OH groups of the diol

Question 21

what is hydrolysis

Answer 21

adding water to the polyester which allows it to break back down into its monomers, reversing condensation polymerisation

Question 22

how to deduce the monomers from the polyester

Answer 22

• then the OH atoms are added back onto the C=O
  and H atoms added onto the oxygen atoms on the other structure

Question 23

what are biopolyesters

Answer 23

a specific type of polymer that are synthesised from sugars and plant oils using microorganisms

they are able to biodegrade naturally in the environment

Question 24

how are esters made and what is the process called

Answer 24

made when alcohols and carboxylic acids react

esterification

Question 25

what is the functional group of esters

Answer 25

R - COO - R where the R symbolises whatever

Question 26

what are esters used for

Answer 26

food flavourings perfumes

Question 27

how to name an ester

Answer 27

- The first part of the name indicates the length of the carbon chain in the alcohol, and it ends with the letters ‘- yl’ - The second part of the name indicates the length of the carbon chain in the carboxylic acid, and it ends with the letters ‘- oate’ - e.g. the ester formed from pentanol and butanoic acid is called pentyl butanoate

Question 28

how is ethyl ethanoate produced

Answer 28

when ethanol and ethanoic acid react in the presence of an acid catalyst

Question 29

what is one characteristic of esters

Answer 29

they are volatile

Question 30

what is the general formula for carboxylic acids

Answer 30

Cn H2n+1 COOH

Question 31

how do carboxylic acid react with metals of carbonates and why

Answer 31

They react with metals to form a salt and hydrogen and with carbonates to form a salt, water and carbon dioxide gas because they behave like other acids they also take part in neutralisation reactions to produce salt and water

Question 32

how to name the salts formed by the reaction of carboxylic acids

Answer 32

they all end -anoate So methanoic acid forms a salt called methanoate, ethanoic a salt called ethanoate etc

Question 33

what is formed in the reaction between ethanoic acid and magnesium and why

Answer 33

magnesium ethanoate and hydrogen carboxylic acid + metal -> metal salt + hydrogen

Question 34

what would be formed in the reaction between potassium hydroxide and propanoic acid

Answer 34

potassium propanoate and water (carboxylic) acid + alkali -> salt + water

Question 35

how do the atoms change when carboxylic acids react to form salts

Answer 35

they lose the last hydrogen and replace it with the metal

Question 36

what is an alcohol in general terms

Answer 36

a colourless liquid that dissolves in water to form neutral solutions

Question 37

what is a use for the first four alcohols

Answer 37

used as fuels

Question 38

what are methanol and ethanol commonly used for and why

Answer 38

SOLVENTS they can dissolve many substances that water cannot such as fats and oils, ASWELL as dissolving most of the things that water can

Question 39

what are the first four alcohols

Answer 39

methanol ethanol propanol butanol

Question 40

how do you name alcohols

Answer 40

remove the final e and replace it with ol

Question 41

what are the three methods of oxidising ethanol

Answer 41

- combustion - microbial oxidation - heating with potassium dichromate(VI) in dilute sulfuric acid

Question 42

what is microbial oxidation

Answer 42

the reaction with oxygen in the air bacteria in the air (acetobacter) use atmospheric oxygen from the air (so this reaction can only occur aerobically)

Question 43

what happens to alcohols when they undergo combustion

Answer 43

they form carbon dioxide and water

Question 44

what colour does ethanol burn with

Answer 44

an almost invisible blue flame

Question 45

what is the formula for when ethanol undergoes microbial oxidation

Answer 45

ethanol + oxygen -> ethanoic acid + water

Question 46

why do wines end up tasting acidic when left open for too long

Answer 46

microbial oxidation of the ethanol - the bacteria form ethanoic acid, the same acid used in vinegar

Question 47

what happens when an alcohol undergoes oxidation

Answer 47

it forms a carboxylic acid

Question 48

what is the formula for when ethanol is heated with acidified potassium dichromate solution

Answer 48

ethanol + [O] -> ethanoic aicd + water

Question 49

during the reaction when ethanol is heated with acidified potassium dichromate solution, what colour change is there and why

Answer 49

the potassium dichromate turns from orange to green dichromte ions turn into chromium ions

Question 50

why does ethanol tend to combust completely when oxidising it through combustion

Answer 50

because of the oxygen atom in the OH group

Question 51

during the reaction when ethanol is heated with acidified potassium dichromate solution, why do we place a condenser above the reaction flask

Answer 51

to prevent the volatile liquids from evaporating and escaping

Question 52

Crude oil fractions

Answer 52

Really gay kids don’t fuck boys Refinery gases Gasoline Kerosene Diesel Fuel oil Bitumen

Question 53

what is esterification

Answer 53

when alcohols and carboxylic acids react to make esters

Question 54

uses of esters

Answer 54

perfumes and food colourings

Question 55

structure of ethyl ethanoate

Answer 55

Question 56

how to name esters eg the ester formed from pentanol and butanoic acid

Answer 56

PENTyl BUTANoate