paper 1

• what is the collision theory

  more kinetic energy- more frequent and successful collisions
• what is activation energy

  minimum amount of energy required for particles to react
• catalyst ...


  increase rate of reaction

  remain unchanged

  alternative path

  lower activation energy
• what is cracking?


  produces short chain alkAnes and alkENes
• what is catalytic cracking?

  vapours passed over hot powdered aluminium oxide catalyst
• alkEnes 


  more reactive than alkanes

  used to produce polymers
• what is the test for alkenes

  bromine water- orange water --> colourless
• hydrocarbons 


  made up of hydrogen and carbon atoms only
• what is fractional distillation 


  separating different liquids based on boiling points
• crude oil


  finite
• complete combustion


  burning with oxygen produced
• what does combustion release

  energy
• what do hydrocarbons depend on

  size of molecules
• fractional distillation process 


  -crude oil is vapourised

  -let gases rise up column

  -vapours condense at diff fractions = depending on boiling points
• what is polymerisation 


  lots of short chain monomers join --> long chain polymers
• Giant covalent molecules


  Substances with many atoms joined together by covalent bonds
• Diamond


  • Form of pure carbon
  • All atoms bonded to four others in a giant tetrahedral network structure
  • Very strong
  • Hardest known natural substance
  • Very high melting point
  • Does not conduct electricity
• Graphite


  • Form of pure carbon
  • All atoms bonded to three others in giant sheets
  • Sheets can slide over each other
• Diamond and graphite are different forms (allotropes) of the element carbon
• Diamond structure


  Rigid network of carbon atoms held together by strong covalent bonds
• Graphite structure


  Layers of carbon atoms with weak forces between the layers
• Graphite has delocalised electrons that can move between the layers, allowing it to conduct electricity
• Diamond does not have free electrons, so it does not conduct electricity
• Uses of diamond


  • Cutting tools (e.g. glass cutters, oil rig drills)
• Uses of graphite


  • Electrodes in batteries
  • For electrolysis
• Lubricant


  Substance that reduces friction between two surfaces
• The weak forces between the layers in graphite allow the layers to slide over each other, making graphite useful as a lubricant
• Giant covalent molecules


  Substances with many atoms joined together by covalent bonds
• Diamond


  • Form of carbon in which all atoms are bonded to four others in a giant tetrahedral network structure
  • Very strong
  • High melting point
  • Does not conduct electricity
• Graphite


  • Form of carbon in which all atoms are bonded to three others in giant sheets which can slide over each other
  • Conducts electricity well
• Graphene


  A single layer of graphite
• Graphene


  • Has strong covalent bonds between carbon atoms
  • Has very high melting point
  • Is very strong
  • Conducts electricity well due to delocalised electrons
• Fullerenes


  Molecules of carbon with hollow shapes, based on hexagonal rings of carbon atoms
• Fullerenes


  • Buckminsterfullerene
  • Nanotubes
• Buckminsterfullerene


  • Molecules made up of 60 carbon atoms arranged in a hollow sphere
  • Has weak intermolecular forces between molecules, so has low melting point and is slippery
• Nanotubes


  • Like a layer of graphene rolled into a cylinder
  • Have high length to diameter ratios
  • Have high tensile strength and resist being stretched
  • Conduct electricity due to delocalised electrons
• Graphene has a giant covalent structure, but fullerenes have large molecules
• Reactivity series


  Shows metals in order of reactivity
• Reactivity of a metal

  Related to its tendency to form positive ions
• Extracting iron and aluminium

  From their ores in various ways