Chapter Name: Electrical Conductivity of Liquids
Activity Name: Electroplating method in Electrical Conductivity of Liquids
In this experiment, the aim is to coat an iron key with copper using the electroplating method. The process involves passing an electric current through a copper sulphate solution, which causes the copper ions to be deposited onto the iron key, creating a copper coating on its surface.
- Copper plate (2 cm x 5 cm) or a flattened copper wire
- Crystals of copper sulphate (blue vitriol)
- Iron key
- Glass beaker
- Sulphuric acid (dilute)
- Copper wires (connecting wires)
Step by Step Procedure:
- Dissolve crystals of copper sulphate in pure water to create a concentrated solution (deep blue in color).
- Pour the copper sulphate solution into a glass beaker and add a few drops of dilute sulphuric acid to increase the electrolyte’s conductivity.
- Tie one end of a copper wire to the iron key, which will be coated with copper.
- Connect the other end of the copper wire to the negative terminal of a battery.
- Suspend the iron key into the copper sulphate solution, ensuring it does not touch the copper plate and is slightly away from it.
- Suspend the copper plate (or flattened copper wire) into the copper sulphate solution from the positive end of the battery through a switch.
- Turn the switch on and allow the circuit to remain active for about 10 minutes.
- After 10 minutes, switch off the circuit and carefully remove the iron key from the solution.
- The iron key gets coated with a shiny, brown color.
- The brown color is due to the deposition of copper on the surface of the iron key.
- If the battery terminals are interchanged, the copper plating process would not occur because the direction of the electric current will be reversed, leading to the copper ions being repelled from the iron key.
- Take care to ensure that the iron key and copper plate do not touch each other during the experiment.
- The experiment should be performed in a well-ventilated area or under a fume hood as sulphuric acid is involved.
Lesson Learnt from Experiment:
The experiment demonstrates the process of electroplating, where one metal is coated with another material through the deposition of ions by passing an electric current through an electrolyte.