Chemistry, 12: Sulfur

Cards (11)

  • What are the uses of sulfur?
    Oil refining
    Fertiliser
    Paper and steel making
    Acid in car batteries
  • How is sulfur produced?
    The contact process
  • What are the sources of sulfur?
    Underground bedrock
    Volcanic deposits
  • Describe the contact process:
    • Sulfur + oxygen is used to make sulfur dioxide
    • Sulfur dioxide is converted into sulfur trioxide by reacting with more oxygen (reversible)
    • Sulfur trioxide + sulfuric acid creates concentrated sulfuric acid (oleum)
    • Oleum + water creates sulfuric acid
  • Why do you need to make oleum?
    Adding sulfur trioxide directly into water would be extremely exothermic and create acid mist
  • What are the conditions for the contact process?
    Catalyst- vanadium oxide (V2O6)
    Temperature- 450C
    Pressure- 2atm
  • The highest yield of sulfur trioxide would be made at low temperatures, which is too slow therefore 450C is used
  • High pressure is not used as the yield is 98%
    Unconverted reactants are recycled
  • What are the equations involved in the contact process?
    S + O2 -> SO2
    2SO2 + O2 ⇌ SO3
    H2SO4 + SO3 -> H2S2O7
    H2S2O7 + H2O -> 2H2SO4
  • Oleum is highly corrosive
    It is a dehydrating agent, absorbing hydrogen and oxygen from compounds in the form of water.
  • When oleum is added to glucose, carbon is formed
    The reaction is highly exothermic, and steam is produced
    A honeycomb structure of black carbon is also formed