Hydrogen v Petrol in Cars

Specification Point 8.14:
  • Evaluate the advantages and disadvantages of using hydrogen, rather than petrol, as a fuel in cars
  • Hydrogen is used in rocket engines and in fuel cells to power some cars.
  • It reacts with oxygen in an exothermic reaction:

2H2 + O2 →2H2O

  • Hydrogen has a series of advantages and disadvantages regarding its use as a fuel:
  • Advantages:
    • It releases more energy per kilogram than any other fuel (except for nuclear fuels).
    • It does not pollute as it only produces water on combustion, no other product is formed.
    • It is a renewable source and is extracted from water by electrolysis.
    • Modern fuel cells are equipped to extract hydrogen from the same water they produce.
  • Disadvantages:
    • Expensive to produce and requires energy for the production process.
    • Difficult and dangerous to store and move around (usually stored as liquid hydrogen in highly pressurised containers).

Fossil Fuels

Specification Point 8.15:
  • Recall that petrol, kerosene and diesel oil are non-renewable fossil fuels obtained from crude oil and methane is a non-renewable fossil fuel found in natural gas
  • Non-renewable fossil fuels are obtained from crude oil by fractional distillation.
  • Petrol is used as a fuel in cars, kerosene is used to fuel aircraft and diesel oil is used as a fuel in some cars, trucks and heavy vehicles such as tanks and trains.
  • There are finite amounts of all three and they all contribute to pollution and global warming.
  • Natural gas consists mainly of methane, CH4
  • This is also a non-renewable fuel as there are finite reserves available.

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Morgan Curtin Chemistry

Author: Morgan

Morgan’s passion for the Periodic Table begun on his 10th birthday when he received his first Chemistry set. After studying the subject at university he went on to become a fully fledged Chemistry teacher, and now works in an international school in Madrid! In his spare time he helps create our fantastic resources to help you ace your exams.