SAASTE Technology/Activities/Electroplating

Processing

Grade 9

ELECTROPLATING
Electroplating is the process of producing a thin metallic coating on a surface of a metal object. This process has wide application in industry, e.g. used as a protective coating to prevent corrosion (chrome plating), to enhance the aesthetics / appearance (copper plating). The process of electroplating involves: Immersing an object to be plated as well as an electrode in a salt of metal solution, sending an electric current through it causing the free metal ions (charged atoms) to be deposited on the object.

Copper plating The following process gives the basics of electroplating and is not a guide for doing practical industrial electro plating.

You will need
 * A plastic or glass container (non metal)
 * (1.5 V cell)
 * Two length of copper wire
 * One coil of copper wire
 * A metal object to copper plate (spoon, nail)
 * Plastic spoon
 * Copper sulphate (the metal salt,) available at most chemist

Copper sulphate is poisonous if swallowed

1. Add 1 teaspoon of copper sulphate to water to make up a solution (about to 400ml.)

2. Strip & connect ­ve lead to object that must be copper plated and place in solution. (For good results make sure object is clean.)

3. Strip coil, connect to positive lead and place coil into the solution



Within a minute the object becomes coated with copper.The electric current splits the COPPER sulphate. The COPPER is deposited on the metal object.

For you to find out:
 * Is it possible to electro plate on a non-metallic object? Please explain your answer.
 * Silver plating, chrome plating, and gold plating are examples of electroplating in industry. The picture shows a watch that was chrome plated. Parts of the plating are eroding. Say what can be done to recoat it. Use the word electroplating in your answer. In the real world getting rid of chemical waste in electro plating is huge problem. What effect does the waste chemical have on the environment?

Author: Robert Solomon

Editor: Osman Sadeck