Chemistry Paper 2

• How do you measure the rate of reaction?

  Rate of reaction = amount of reactant used/time
• What factors affect the rate of reaction?

  • concentration
  • pressure
  • surface area
  • temperature
  • catalysts
• What is the collision theory?

  Chemical reactions can occur only when reacting particles collide with each other and with sufficient energy
• What is activation energy?

  The minimum amount of energy that particles must have to react
• How can you increase the frequency of collisions and so rate of reactions?

  • increasing the concentration of reactants
  • increasing the pressure of reacting gases
  • increasing the surface area of solid reactants
• What is a catalyst?


  A substance that speeds up chemical reactions without being changed or used up
• What do enzymes do in a reaction?

  Act as catalysts
• What do catalysts do?

  • decrease activation energy
  • provide different ways for chemical reactions to use less activation energy
• What are the characteristics of crude oil?

  • finite
  • remains of ancient biomass and plankton
  • mixture of many compounds
  • made of hydrocarbons
• What is the formula for hydrocarbons?

  CₙH₂ₙ₊₂
• What are the first four Alkanes?

  • Methane
  • Ethane
  • Propane
  • Butane
• What is the acronym used to remember alkanes?

  • Monkeys
  • Eat
  • Peanut
  • Butter
• How does fractional distillation work?

  • oil is heated
  • oil evaporates and condenses at different temperatures
  • the hydrocarbons are separated into fractions of similar carbon atoms
• What are the fuels and oils created by distilled crude oil?

  • Petrol
  • Diesel oil
  • Kerosene
  • Heavy fuel
  • Petroleum gases
• What does viscous mean?

  Thick and not runny
• What are the properties of hydrocarbons?

  • Shorter the molecules, the less viscous
  • The longer the molecules, the more viscous
  • The shorter the molecules, the lower the boiling point
  • The shorter the molecules, the more flammable
• What is the burning equation for hydrocarbons?

  hydrocarbons ---> carbon dioxide + water
• What happens to hydrogen and carbon in the burning of a hydrocarbon?

  They are oxidised
• What are the different ways of cracking?

  • Passing the hydrocarbons over a hot catalyst
  • Heating them to a high temperature for thermal decomposition to take place
• What is the formula for Alkenes?

  CnH2n
• What are the first two alkenes?

  • Ethene
  • Propene
• What do Alkenes react with?

  Bromine water
• What happens to alkenes in a reaction with Bromine water?


  They turn from orange to colourless
• Why are alkenes more reactive than alkanes?

  They have a double bond
• What are alkenes used to produce?

  Polymers
• How is ethanol produced?

  The fermentation of sugar with yeast
• What is a pure substance?

  A single element or compound not mixed with any other substance
• What is a key feature of a pure substance?


  They melt and boil at specific temperatures which can be used to distinguish them from mixtures
• What is a formulation?


  A mixture that has been designed as a useful product for a specific purpose
• How are formulations made?


  By mixing the components in carefully measured quantities to ensure that the product has the required properties
• What are some formulations?

  • Fuels
  • Paints
  • Medicines
• What is chromatography used for?

  Separating mixtures to identify the substances in them
• How do you tell how soluble a substance is with chromatography?

  The higher up it moves on the paper, the more soluble it is
• How do you test for hydrogen?

  • A burning splint held at the open end of a test tube
  • Creates a squeaky pop sound if hydrogen is present
• How do you test for oxygen?

  • A glowing splint inserted into a test tube
  • Splint will relight if oxygen is present
• How do you test for carbon dioxide?

  • Bubble the gas through limewater
  • Water will turn milky if carbon dioxide is present
• How do you test for chlorine?

  • Use damp litmus paper in chlorine gas
  • Litmus paper will turn white and bleach if chlorine gas is present
• What can we use Earths resources for?

  • warmth
  • shelter
  • food
  • transport
  • energy
• What are renewable energy sources?

  Sources of power that quickly replenish themselves and can be used again
• What are finite resources?

  Resources that have a limited supply that will eventually run out