Hydrogen vs Fossil Fuels (Edexcel GCSE Chemistry): Revision Note

Hydrogen as a Fuel

Hydrogen as a fuel

• Hydrogen is used in rocket engines and in fuel cells to power some cars and buses

• 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

• 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)

  • The production of hydrogen process releases carbon dioxide 

Fossil Fuels

• A fuel is a substance which when burned, releases heat energy

• This heat can be transferred into electricity, which we use in our daily lives

• Most common fossil fuels include coal, natural gas and hydrocarbons such as methane and propane which are obtained from crude oil

• The main constituent of natural gas is methane, CH₄

• Most of the world's energy supply still comes from fossil fuels:

Over 80% of the world's energy supply still comes from fossil fuels