This is a really simple way to show how we can chemically generate electricity using everyday equipment.
A voltaic cell, named after Alessandro Volta, is an electrochemical cell that derives electrical energy from the flow of electrons from one metal to another, this is driven by oxidation and reduction reactions (redox) (depending on the loss or gain of electron at the metals). In this instance using Zinc and Copper the electrons are lost from the zinc (oxidation) and are gained by the copper (reduction).
This practical is a really interesting practical for physics and chemistry subjects for example electrochemical cells, electricity and oxidation and reduction (redox) reactions. It is also a really fun STEM club activity (survival science, how to survive the Zombie apocalypse).
- copper coins or copper metal discs
- zinc washers or zinc metal/zinc metals coins (can also use aluminium foil or a 10p)
- vinegar or weak acid/salt water/lemon juice as your electrolyte (wear eye protection)
- cotton pads or thin cardboard/blotting paper
- strip of aluminium (to act as a connector at the bottom of the pile)
- low power LED
- insulated wires to connect the bottom and top metals together (they should be different) and to connect a LED or voltmeter
- multimeter or voltmeter
- electrical tape (to hold cells together for your torch)
- Soak your cotton pads or cardboard in your electrolyte for a few minutes (making sure they don’t fall apart).
- Place an aluminium strip on your work surface (can do this in a tray).
- Place a copper coin on the aluminium.
- Take a soaked cotton pad and place this on the copper coin (needs to be cut to be the same size as the coil, otherwise it can short-circuit).
- Place a zinc washer on the cotton pad (should be a similar size to the coin).
- You should now have a one cell (copper/electrolyte/zinc).
- Place multimeter on aluminium connector and on the zinc and you should get a voltage reading of around 0.5V.
- Repeat the steps and create another cell starting with another copper coin.
- Once you have a few cells try a LED to create a small torch with your chemically generated electricity.