Hydrocarbons and Polymers Flashcards
What is the general formula for the alkanes?
CnH2n+2 (n = number of carbon atoms)
How many bonds do carbon atoms need to have in alkanes and alkenes?
4
Are alkanes saturated?
Yes, they only have C-C bonds, not C=C bonds
What is the general formula of alkenes?
CnH2n
What is the general word equation for a reaction between an alkene and oxygen?
Alkene + oxygen → carbon dioxide + water
Write the word equation for a reaction between ethene and bromine
Ethene + bromine → diobromoethane (C2H4Br2)
Are alkenes saturated?
No, they’re unsaturated as they have C=C bonds
What is the test for alkenes?
Add a few drops of bromine water to the substance that you’re testing, if it stays orange it’s an alkane, if it’s decolourised then it’s an alkene
What are addition polymers?
Relatively large molecules made by combining smaller molecules containing C=C bonds. Polymers have high relative atomic mass, they’re made up of small repeating units
What are the properties and uses of poly(ethene)?
Flexible, cheap, good electrical insulator. Used for plastic bags, plastic bottles and clingfilm
What are the properties and uses of poly(propene)?
Flexible, shatterproof, has a high softening point(similar to melting point). Used in buckets and bowls
What are the properties and uses of poly(chloroethene) (PVC)?
Tough, cheap, long lasting, good electrical insulator. Used in window frames, gutters and pipes, insulation for electrical wires
What are the properties and uses of poly(tetrafluoroethene)?
Tough, slippery, resistant to corrosion, good electrical insulator. Used in non-stick coatings for frying pans, containers for corrosive substances and insulation for electrical wires
What are polyesters?
Condensation polymers
Which 2 different monomers do polyesters need?
A molecule containing two carboxylic acid groups and a molecule containing two alcohol groups
When is an ester link formed?
Each time two different monomers react together
How many products are formed in condensation polymerisation?
2, water molecules and a polymer
What structure does DNA have?
Double helix, there are 4 bases, A pairs with T, G pairs with C
What are the monomers for DNA?
Nucleotides
What are the monomers for proteins?
Amino acids
What is the monomer for starch?
Glucose
What is the main raw material needed to make addition polymers and most condensation polymers?
Crude oil
How can polymers be disposed of?
- Landfill, this is negative because polymers are not biodegradable so they last for many years, we are also running out of landfill sites
- Burning, this is negative because polymers release toxic gases when they burn
- Recycling, positive
- Biodegradable polymers are being developed, positive
What are the positives of landfill sites?
- Waste is disposed of quickly
- Waste is out of sight once it’s covered over