Topic 5 - Fuels

  1. What are fuels?
    Chemicals which give out energy when they burn
  2. What is the test for oxygen gas?
    It relights a glowing splint
  3. What, roughly, is the percentage of oxygen and nitrogen in the air?
    • Oxygen - 20%
    • Nitrogen - 80%
  4. Reactions that give out heat are said to be _______ reactions?
  5. What are the three main fossil fuels?
    Coal, oil and natural gas
  6. How are fossil fuels formed?
    They are formed from dead plant and animal remains over millions of years under heat and pressure
  7. What consists of a mixture of compounds which are mostly hydrocarbons?
    Crude oil
  8. What process is used to seperate crude oil into fractions?
    Fractional distillation
  9. The higher the viscosity the _______ the liquid is?
  10. As the size of the molecules in the fractions increases the boiling point of the fraction ________ too?
  11. What fractions are the most flammable?
    The low boiling point fractions
  12. What are hydrocarbons?
    Molecules that contain hydrogen and carbon only
  13. What is the test for carbon dioxide?
    It turns lime water from clear to milky/chalky
  14. What do hydrocarbons produce when they are burned?
    Carbon dioxide and water
  15. If a hydrocarbon burns in a limited supply of oxygen it may produce....?
    Carbon monoxide
  16. What does burning fuels with the element sulphur produce?
    Sulphur dioxide
  17. What does sparking air in a car engine produce?
    Oxides of nitrogen
  18. What do oxides of nitrogen dissolve in rain to form?
    Nitric acid (acid rain)
  19. How can we decrease air pollution?
    • By altering the fuel to air ratio
    • By using catalytic convertors which convert pollutant gases into harmless ones
  20. What metals are used in catalytic convertors?
    Platinum, rhodium and palladium
Card Set
Topic 5 - Fuels
Standard Grade Chemistry - Topic 5 - Fuels