Organic Chemistry

• What is a hydrocarbon?

  A compound containing of only hydrogen and carbon atoms.
• How is crude oil formed?

  Over millions of years from the remains of ancient biomass.
• What are the alkanes?

  Hydrocarbons that only have single bonds.
• What are the first four alkanes?

  Methane, ethane, propane and butane.
• What is the general formula for alkanes?

  CnH2n+2.
• How does boiling point depend on the chain length?

  The longer the chain length the higher the boiling point.
• How does viscosity depend on the chain length?

  The longer the chain, the higher the viscosity.
• How does flammability depend on the chain length?

  The longer the chain, the lower the flammability.
• How can the different alkanes in crude oil be separated?

  Fractional distillation
• What is a fraction?

  A group of hydrocarbons with similar chain lengths.
• Name five useful fuels produced from fractional distillation?

  Petrol, diesel oil, kerosene, heavy fuel, liquefied petroleum gases.
• Name four useful materials produced from crude oil?

  Solvent, lubricants, polymers and detergents.
• What is cracking?

  Breaking down a hydrocarbon with a long chain into smaller molecules.
• Name two methods to carry out cracking?

  Stream cracking and catalytic cracking.
• What are the products of cracking?

  Short chain alkanes and alkenes.
• What are alkenes?

  Hydrocarbons with a double bond.
• What are alkenes used for?

  Formation of polymers.
• Describe the reactivity of alkenes compared to alkanes.

  Alkenes are very reactive.
• How can you test for alkenes?

  Alkenes turn orange bromine water colourless