Lecture 5 – Electroplating

ACKNOWLEDGEMENT:

Figure	Source of Figure
Figure 6a	http://www.explainthatstuff.com
Figure 6b	http://projects.nfstc.org

Industrial uses of electrolysis:

1. Purification of raw copper to pure copper using impure copper as the anode, pure copper as the cathode and copper sulphate solution as the electrolyte.
2.  Extraction of Aluminium from the mixture of its molten ore and cryolite.

Electrolysis for Electroplating:

Electroplating is defined as covering a metal with another metal to preserve, protect or polish it.

Figure 6a:

For electroplating:

1. the metal to be electroplated is made as the cathode
2. the metal used for electroplating is made as the anode
3. the electrolyte used is the salt solution of the metal used for electroplating

Figure 6b:

The process of electrolysis deposits a thin, uniform and smooth layer of the electroplating metal on the electroplated metal.

Here:

1. Iron spoon to be electroplated is made as the cathode 
2. Silver used for electroplating is made as the anode
3. Silver nitrate is used as the electrolyte 

Industrial use:

i.                    Copper plating on iron to prevent rusting

ii.                  Gold plating for jewelries and watches