Chemical Effects of Electric Current
The passing of electric current through liquids or conducting solutions causes chemical reaction. More importantly, chemical activity may occur in the liquids around the electrodes.
Bubbles of gas are formed, deposits of metal may be seen and changes of colour may occur on the electrodes.
This reaction depends on what liquids and electrodes are used.
The passing of electric current through a liquid causes chemical changes. This process is known as electrolysis.
- Take two discarded cells.
- Take out carbon rods from the cells.
- Clean their metal cap with sand paper.
- Wrap copper wires around the metal caps of carbon rods and join them to a battery.
- These rods are known as electrodes.
- Now, pour a cup full of water in a glass or plastic bowl and add a teaspoonful of salt or a few drops of lemon juice to water to make it more conducting.
- Immerse the electrodes in this solution.
- Make sure that the metal caps of the carbon rods are outside the water and wait for 3 - 4 minutes.
- Observe the electrodes. You will notice the gas bubbles near the electrodes.
- This is known as chemical change.
Visualisation : Put the same picture which is in the top. But, instead of copper sulphate solution, mark it as water. Copper plate as carbon rod. The label is Passing current through water.