GCSE Chemistry · AQA 8462 · Topic 4.5.2
Chemical cells and fuel cells
Key points
- A chemical cell contains two different metals (electrodes) in contact with an electrolyte. The bigger the difference in reactivity of the metals, the bigger the voltage.
- A battery is two or more cells connected in series to give a larger voltage.
- In non-rechargeable cells the reaction stops when a reactant is used up. Rechargeable cells can be reversed by applying an external current.
- A hydrogen fuel cell is supplied with hydrogen and oxygen (from air); the hydrogen is oxidised to make electricity, and the only product is water.
- Fuel cells: no pollutants at the point of use and no need for recharging, but hydrogen is a flammable gas that is hard to store, and producing it often uses fossil fuels.
- (Higher) Half equations: at one electrode ; at the other .
Topic notesPremium
A chemical cell turns the energy of a chemical reaction directly into electricity. Batteries and hydrogen fuel cells both work this way. This sub-topic is chemistry only.
Unlock the full notes with Premium
Premium includes full topic notes, the paper generator, self-quizzes and progress tracking.
Practise this topicPremium
Premium members can generate an exam-style paper with a mark scheme, or take a quick quiz, on Chemical cells and fuel cells.