C7 - Organic Chemistry

Crude oil
1. Provides fuel for most modern transport
  1. Diesel oil
  2. Kerosene
  3. LPG
  4. Heavy fuel oil
Alkanes and alkenes
1. Alkanes
  1. C_n H_2n+2
  2. Bromine water stays orange
2. Alkenes
  1. C_n H_2n
  2. Bromine water decolourises
Fractional Distillation
1. Oil is heated until most is gas
  1. Gases enter fractionating column, liquid is drained off
    1. Longer hydrocarbons have higher boiling points, condense back into liquids
      1. Shorter ones drain out later on towards top of column
Hydrocarbons
1. Longer chain
  1. Boiling point increases
  2. Viscosity increases
  3. Colour darkens
  4. Number of carbon atoms increases
2. Combustion
  1. hydrocarbon + oxygen = carbon dioxide + water (+ energy)
  2. Both carbon and hydrogen are oxidised
  3. Hydrocarbons used as fuels because of energy released when they combust completely
Cracking
1. Produces an alkene and an alkane
2. Makes long chain hydrocarbons shorter
  1. Heat them to vaporise them
    1. Catalytic cracking
      1. Vapour passed over hot powdered aluminium oxide catalyst
        Splits apart molecules
    2. Steam cracking
      1. Mix with steam
        Heat to a very high temperature
3. Thermal decomposition reaction

Resource summary

	Created by Lilac Potato almost 7 years ago