Free Hydrogen–oxygen fuel cells questions for IGCSE Chemistry (0620), part of Electrochemistry. Each question has the answer and the marking points an examiner would look for.
Generate a full Hydrogen–oxygen Fuel Cells worksheet →All Electrochemistry questionsA hydrogen–oxygen fuel cell is used to power a car.
1 Electricity is produced directly from the chemical reaction.
2 The overall reaction is 2H2 + O2 → 2H2O.
3 Hydrogen is easy to store safely at high pressure in a car.
Which statements are correct?
Answer: B
Which is a disadvantage of hydrogen as a fuel for cars?
Answer: A
Which term is described by this statement?
“A cell that uses hydrogen and oxygen to produce electricity, with water as the only product.”
Answer: A
A fuel cell uses hydrogen and oxygen to produce electricity.
State the energy change in a fuel cell.
Hydrogen is often made from methane. Explain why this reduces the environmental benefit of fuel cells.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | chemical → electrical chemical energy to electrical energy B1 | 1 |
| (b) | produces CO₂ from fossil fuel methane is a fossil fuel B1 making hydrogen from it releases carbon dioxide B1 | 2 |
A hydrogen–oxygen fuel cell is used to power a car.
Write the overall equation for the reaction in the fuel cell.
Give two advantages of fuel cells compared with petrol engines.
Give one disadvantage of hydrogen fuel cells.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | 2H₂ + O₂ → 2H₂O correct formulae B1 balanced B1 | 2 |
| (b) | only water produced; more efficient only product is water (no CO₂/pollutants) B1 more efficient B1 | 2 |
| (c) | hydrogen storage/production Any 1 of: hydrogen is difficult to store (explosive/needs high pressure); hydrogen is often produced from fossil fuels B1 | 1 |
Compare fuel cells with petrol engines.
Give two disadvantages of fuel cell cars.
| Part | Answer and marking points | Marks |
|---|---|---|
| storage; few filling stations; cost Any 2 of: hydrogen is hard to store (high pressure/explosive); few hydrogen filling stations; expensive B2 | 2 |
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