Galvanic cells are a clear representation of what is happening inside a battery. Experiencing the operation of these cells through constructing and observing them will help you to understand the concepts involved with the chemical reactions in batteries.
Steps to be taken
1. Make sure all the metals to be used in this experiment are clean and shiny before use. That will help us to be sure that the results are not due to previous dirt on the metals.
2. Place a teaspoon of salt in each glass and fill them with water. Stir the water until all the salt in each glass has dissolved. Roll up the tissue paper into a tube, then flatten it. Do the same with the aluminium foil. Then set up the equipment as shown:
3. If you have electrical wire with no clips, make sure it is firmly connected to both the nail and the foil. Leave this setup somewhere for a few days. Top up the liquid levels if needed; the tissue needs to be wet and dipping into the water in both glasses.
How it Happens?
In this experiment, the aluminium is giving electrons to the iron to stop it rusting and is therefore corroding itself. This time the electrons are traveling through the wire to the iron nail. This is in effect a very simple, low voltage battery. If you have a very sensitive volt meter or the like you will be able to detect the current passing through the wire.
two drinking glasses
one large iron nail
some aluminum foil
some copper wire
a length of electrical wire, preferably with alligator clips on each end