Fractional distillation

• fractional distillation: separates a mixture of liquids into two or more fractions
• The crude oil is heated and vapourised before being passed into the fractionating column. Fractions are separated based on their boiling points. Small molecules have a lower boiling point as they have weaker forces holding them together and collect at the top of the column
• Complete combustion

  Fuel + oxygen -----> carbon dioxide + water + energy
• Incomplete combustion

  Fuel + insufficient oxygen ----> water + carbon + carbon monoxide
• Cracking is where larger hydrocarbons are broken down into smaller ones producing a short chain alkane and an alkene
• Test for alkanes: bromine water stays orange
• Test for alkenes: bromine water goes from orange to colourless
• Saturated: all bonds are single bonds
• Hydrocarbons: compounds that are made of carbon and hydrogen only