Organic chemistry

• What do hydrocarbons contain?

  Hydrogen and carbon atoms
• What type of bonds do alkane have?

  C-C Single bonds
• What's the general formula for alkanes?

  CnH2n+2
• What's the formula for methane?

  CH4
• What's the formula for ethane?

  C2H6
• What's the formula for propane?

  C3H8
• What's the formula for butane?

  C4H10
• When do hydrocarbon properties change?

  As the chains get longer
• When does complete combustion occur?

  When there's plenty of oxygen
• What's the equation for complete combustion?

  Hydrocarbon + oxygen -> co2 + water
• What happens during combustion?

  Carbon and hydrogen are oxidised
• What are hydrocarbon used as in complete combustion?

  Fuels because of the amount of energy released when they combust
• What's crude oil?


  A fossil fuel formed from the remains of plants and animals mainly plankton
• Why is fractional distillation used?

  To seperate hydrocarbon fractions
• How does fractional distillation work?

  The oil is heated until most of it has turned to gas which enter a fractionating column.

  The longer hydrocarbons have higher boiling points. They condense back into liquids and drain out the column. End up with oil mixture in different fractions
• What is crude oil used for?

  Fuel for transport

  Feedstock to make new compounds
• What's cracking?


  Splitting up long-chain hydrocarbons
• What does cracking produce?

  Alkanes
• How is bromine water used to test for alkanes?


  When orange bromine water is added to alkanes nk reaction will happen and it'll stay orange. If its added to an alkene the bromine reacts with the alkene to make a colourless compound
• What is cracking?


  A thermal decomposition reaction that breaks down molecules by heating them
• What is catalytic cracking ?


  Heating long-chain hydrocarbons to vaporise them. The vapour is passed over a hot catalyst which splits the molecules apart on the surface
• What's steam cracking?


  Vaporising hydrocarbons and mixing them with steam and heating them to a very high temperature
• What are the properties of short carbon chains?

  More runny

  Lower boiling points

  More flammable
• What are the waste products in complete combustion?

  Carbon dioxide and water vapour