New
New
Year 11
OCR
Foundation

Fuel cells

I can describe how a hydrogen fuel cell works and compare one to an electric cell.

New
New
Year 11
OCR
Foundation

Fuel cells

I can describe how a hydrogen fuel cell works and compare one to an electric cell.

Lesson details

Key learning points

  1. One type of fuel cell contains hydrogen that reacts with oxygen from the air to produce a voltage.
  2. Hydrogen used in fuel cells can be extracted from fossil fuels or produced by electrolysis powered by the National Grid.
  3. Other fuel cells exist, but have other products than just water.
  4. There are many strengths and weaknesses of fuel cells, and these should be compared against other energy sources.

Common misconception

Confusing electrode reactions with those that occur in electrolysis. For example in a hydrogen fuel cell, hydrogen is oxidised at the anode but in electrolysis, hydrogen is produced at the cathode.

Discuss the electrode reactions in terms of electron loss or gain; rather that just relying on memory. This will provide pupils with the tools to work out the electrode reactions.

Keywords

  • Fuel cell - a device that produces a voltage when supplied with a fuel and oxygen

  • National Grid - the network that connects all the power stations in the country to make sure that everywhere has access to electricity

  • Fossil fuel - a fuel that formed over millions of years from the dead remains of organisms

This lesson provides a good opportunity to revisit some ideas met earlier in the course such as fossil fuels, greenhouse gases, renewable / non–renewable energy sources and climate change.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
What is a chemical reaction?
Correct answer: A process that changes substances into new substances.
A process that evaporates substances.
A process that freezes substances.
Q2.
What is a hydrocarbon?
A compound made of carbon and nitrogen atoms only.
Correct answer: A compound made of hydrogen and carbon atoms only.
A compound made of hydrogen and oxygen atoms only.
Q3.
What is one product of hydrocarbon combustion?
Correct answer: Carbon dioxide
Nitrogen
Oxygen
Q4.
What is a fossil fuel?
Correct answer: A fuel formed over millions of years from the remains of organisms.
A fuel made from renewable resources.
A fuel made from synthetic materials.
Q5.
What is the National Grid?
A network of gas pipelines.
A system for delivering water.
Correct answer: The network that connects power stations to provide electricity everywhere.
Q6.
What is one environmental impact of using fossil fuels?
Increase in oxygen levels.
Reduction in water pollution.
Correct answer: Release of greenhouse gases.

6 Questions

Q1.
What is a fuel cell?
Correct answer: A device that produces a voltage when supplied with a fuel and oxygen.
A device that stores electricity for later use.
A device that produces fuel from water and sunlight.
Q2.
What is the word equation for the overall reaction in a hydrogen fuel cell?
Hydrogen + Carbon Dioxide → Water
Correct answer: Hydrogen + Oxygen → Water
Hydrogen + Nitrogen → Ammonia
Oxygen + Carbon → Carbon Dioxide
Q3.
What happens at the anode in a hydrogen fuel cell?
Correct answer: Hydrogen is oxidised into hydrogen ions and electrons.
Oxygen molecules are split into protons and electrons.
Hydrogen ions and electrons react with oxygen to produce water.
Q4.
What is the reaction at the anode in a hydrogen fuel cell?
Correct answer: 2H₂ → 4H⁺ + 4e⁻
H₂ + O₂ → H₂O
O₂ + 4H⁺ + 4e⁻ → 2H₂O
Q5.
What is one advantage of fuel cells?
Low efficiency
High emissions
Loud operation
Correct answer: No carbon dioxide is formed
Q6.
What is one challenge of using fuel cells?
Correct answer: High cost
High emissions
Low efficiency