# State two advantages and two disadvantages of using hydrogen-oxygen fuel cells to generate electricity.

> Cambridge International IGCSE Chemistry (0620) — 4.2 Hydrogen-oxygen fuel cells · State · 4 marks

## Mark scheme (4 marks)

1. Advantage 1: The only product/waste released is water (no carbon dioxide or polluting exhaust gases produced)
2. Advantage 2: More efficient than combustion engines / produces electrical energy directly without burning fuel / continuous supply of electricity as long as fuel is supplied
3. Disadvantage 1: Hydrogen is difficult/expensive to store or transport (hydrogen is a flammable/explosive gas; requires high-pressure tanks or cryogenic storage)
4. Disadvantage 2: Hydrogen is mainly produced from fossil fuels (e.g. steam reforming of methane), so its production is not fully clean / expensive to produce by electrolysis using renewable energy

## Key terms

- [fuel cell](https://www.gradenine.co.uk/glossary/fuel-cell)
- [hydrogen](https://www.gradenine.co.uk/glossary/hydrogen)

## Related

- [Revision notes for Cambridge International IGCSE Chemistry (0620)](https://www.gradenine.co.uk/learn)
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Source: [GradeNine](https://www.gradenine.co.uk/q/state-two-advantages-and-two-disadvantages-37b3f164) · Published by Druglandscape Ltd.