Chemistry P2 Flashcards
(48 cards)
What are addition polymers made from?
Alkenes or alkanes? Why?
Unsaturated monomers
Alkenes = double covalent bond - can open double bonds and join together to form polymer chains (addition polymers)
What is needed for monomers to join together to create a polymer?
Pressure
Catalyst
Naturally occuring polymers?
DNA
Starch
Proteins
(DNA from 4 different monomers)
(Starch = polymer of glucose)
(Proteins = polymer of amino acids)
What is the polymer - poly(ethene) used for?
Properties?
Properties:
- flexible
- electrical insulator
- cheap
Uses:
- plastic bags
- bottles
- wire insulation
What is the polymer - poly(propene) used for?
Properties?
Properties:
- flexible
- strong
- tough
- malleable
Uses:
- crates
- furniture
- ropes
What is the polymer - poly(chlroroethene) used for?
Properties?
Properties:
- tough
- cheap
Uses:
- window frames
- water pipes
What is the polymer - poly(tetrafluroethene) used for?
Properties?
Properties:
- unreactive
- tough
- non-stick
Uses:
- non-stick pans
- waterproof clothing
What are the advantages and disadvantages of recycling polymers?
Advantages:
- Reduces amount of non-biodegradable waste in landfill
- Decreases emissions released from burning polymers
- Recycling uses less water and energy resources than new ones
- Decreases amount of crude oil needed to produce more plastics
- Saves money + new jobs
Disadvantages:
- Must be separated by type before melted and reformed into new product (difficult and £££)
- If mixed = quality decreases and strength decreases
- Melting polymers can release dangerous gases that harm plants and animals
Why is it important to find environmental way to dispose of polymers?
Landfill sites:
- lots of plastic dumped in landfill
- usually when polymers are too difficult or £££ to recycle
- lots of valuable used for landfill
- most polymers = biodegradable
Combustion:
- Burning plastics produces a lot of energy - can be used to generate electricity BUT:
- if not carefully controlled = toxic gases released from combustion of plastics (e.g PVC burned = HCI - has to be removed)
- Carbon dioxide produced = global warming
Polymers are made from….
Can be separated by……… which is then …….. and………and…….to be used as useful chemicals
Crude Oil
Fractional Distillation
Further purified
Cracked
Refined
In order to carry out a flame test:
- Light a Bunsen burner to produce a hot…..
- Pick up a small sample of………… using a …….. ………………, cleaned in…..
- Hold sample in….. of flame and observe flame colour
- …blue flame
- solid salt - PLATINUM WIRE LOOP, … cleaned in HYDROCHLORIC ACID
- …in edge of flame
What is the positive flame test colour for a LITHIUM metal ION?
RED
What is the positive flame test colour for a SODIUM metal ION?
YELLOW
What is the positive flame test colour for a POTASSIUM metal ION?
LILAC
What is the positive flame test colour for a CALCIUM metal ION?
ORANGE/RED
What is the positive flame test colour for a COPPER metal ION?
BLUE/GREEN
In order to carry out the hydroxide precipitate test for metal cations:
- Dissolve a little …………….. in a test tube using ………….
- Add a few drops of ………………………..solution, 1 drop at a time.
- Record colour of any precipitate formed.
- If a ……… precipitate forms, add ……………………………………..solution to see if it will disappear to leave a ……………..solution.
- Solid salt -….distilled water
- Dilute sodium hydroxide solution
- EXCESS dilute sodium hydroxide to leave a CLEAR/COLOURLESS solution.
Test for ammonium ions:
- Dissolve a little …………. in a test tube using …………….
- Add………………………..solution and warm gently with Bunsen burner flame.
- Remove from flame. Hold a piece of……………………………near mouth of test tube. If ammonia present, turns…..
- Solid salt -….. distilled water
- DILUTE SODIUM HYDROXIDE
- DAMP RED LITMUS PAPER - turns BLUE
Hydroxide Precipitate Test for Metal Cations:
What colour does Iron(2) ION turn with dilute SODIUM HYDROXIDE?
GREEN
Hydroxide Precipitate Test for Metal Cations:
What colour does Iron(3) ION turn with dilute SODIUM HYDROXIDE?
BROWN
Hydroxide Precipitate Test for Metal Cations:
What colour does Copper ION turn with dilute SODIUM HYDROXIDE?
BLUE
Hydroxide Precipitate Test for Metal Cations:
What colour does Calcium ION turn with dilute SODIUM HYDROXIDE?
WHITE
Hydroxide Precipitate Test for Metal Cations:
What colour does Aluminium ION turn with dilute SODIUM HYDROXIDE?
WHITE - excess NaOH = COLOURLESSsolution
Test for Carbonate ions:
- Put a little ……………. in a test tube and add a few drops of ………………
- Record whether any ……………. occurs.
- Use …………… to check that any ……………. contain carbon dioxide.
- Solid salt ….. dilute hydrochloric acid
- Effervescence
- Limewater ….. bubbles