Chemical Cells and Batteries
Revise Chemical Cells and Batteries for GCSE Chemistry with this free worksheet and full mark scheme — Foundation and Higher exam-style questions with worked answers for AQA, Edexcel and OCR. A separate (triple) chemistry topic on how cells produce a voltage and why non-rechargeable cells eventually stop working.
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These worksheets and mark schemes are original, written for Virtus Academy and checked against the current AQA, Edexcel and OCR specifications. Every worksheet comes with a full mark scheme.
Topic overview
Cells contain chemicals that react to produce electricity. This is a Triple-only topic.
A simple cell is made by connecting two different metals in an electrolyte. The voltage produced depends on two things: the difference in reactivity between the two metals, and the type of electrolyte used. A greater difference in reactivity gives a larger voltage.
A battery is two or more cells connected in series, which produces a greater voltage than a single cell. In non-rechargeable cells the reaction stops when one of the reactants is used up, and the reaction cannot be reversed. Rechargeable cells can be recharged because the reaction can be reversed by an external electrical current.
Revision notes
How a simple cell works
Two different metals are connected and placed in an electrolyte.
A voltage is produced. The size of the voltage depends on the difference in reactivity between the two metals and on the type of electrolyte used.
Batteries
A battery consists of two or more cells connected in series.
This produces a greater total voltage than a single cell alone.
Rechargeable and non-rechargeable
In non-rechargeable cells such as alkaline batteries, the reaction stops when one reactant is used up and cannot be reversed.
Rechargeable cells can be recharged because the chemical reactions are reversed when an external electrical current is supplied.
Key points
- A cell produces electricity from chemical reactions.
- Two different metals are needed in an electrolyte.
- Voltage depends on the reactivity difference.
- Voltage also depends on the electrolyte.
- A battery is two or more cells in series.
- Rechargeable cells reverse their reactions.
Worked examples
Example 1
State two factors that affect the voltage produced by a simple cell. [2 marks]
Model answer
The difference in reactivity between the two metals used (1 mark), and the type of electrolyte used (1 mark).
Example 2
Explain why a non-rechargeable cell eventually stops working. [2 marks]
Model answer
One of the reactants in the cell is used up (1 mark), and because the reaction cannot be reversed, no more electricity can be produced (1 mark).
Example 3
Explain how a rechargeable cell differs from a non-rechargeable one. [2 marks]
Model answer
In a rechargeable cell the chemical reactions can be reversed (1 mark) when an external electrical current is supplied, so the cell can be used again (1 mark).
Common mistakes
Saying two of the same metal will work.
Two different metals are needed, because a reactivity difference is required.
Confusing a cell and a battery.
A battery is two or more cells connected in series.
Giving only one factor affecting voltage.
Both the reactivity difference and the electrolyte matter.
Forgetting this is Triple-only.
It is not required for Combined Science.
Exam tips
- Give both factors affecting voltage when asked.
- Distinguish a cell from a battery precisely.
- Explain rechargeability through reversing the reaction.
- Remember this is a Triple-only topic.
Key terms
- Cell
- A device producing electricity from chemical reactions.
- Battery
- Two or more cells connected in series.
- Electrolyte
- The solution in which the electrodes are placed.
- Rechargeable
- Able to have its reactions reversed by an external current.
Related topics
Written and reviewed against the current AQA, Edexcel and OCR specifications. Spotted an error? Let us know.