A lemon Cell
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This battery can be made with almost any fruit. The metal electrodes can be varied but must be different metals.
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Assemble the apparatus as in the diagram on the right. Push the pieces of metal firmly into the lemon to act as
electrodes. They must not touch one another. Clip the crocodile clips onto the electrodes and wire them to a bulb. Provided the bulb is sufficiently low voltage it will light. A battery powered digital clock sometimes works where a bulb will not because bulbs draw larger
currents than digital displays.
This cell provides about 1V. If a large voltage is required they can be connected together in series[?]. Connect the copper electrode of one cell to the zinc electrode of another cell.
Both oxidation and reduction occur.
A lemon cell is more complicated than a simple cell.
Zinc is oxidised
- Zn --> Zn2+ + 2 e-
Hydrogen is reduced
- 2H++ 2e- --> H2
Hydrogen is also reduced at this electrode.
- 2H++ 2e- --> H2