Electrolysis

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A substance whose aqueous solution can conduct electric current is
called electrolyte.

The points at which electric curent enters or leaves an electrolyte
are called electrodes.

Cathode is that electrode at which electrons enter the electolyte.

Anode is that electrode at which electrons leave the electrolyte.

A substance whose aqueous solution cannot conduct electic current is
called non-electrolyte.

Decomposition of an electrolyte, by passage of electric current
through it, is called electrolysis. Ions are the carriers of charge in
electrolytic conduction.

Electroplating :

Electroplating is a process in which an object made of a conducting
material (usually a metal) is coated with a less active metal using
electrolysis technique.

Process :

The article to be electroplated is used as cathode.

A rod or a plate of the less active metal i.e. of coating material, is
used as anode.

These electrodes are immersed in a solution of electrolyte having
cations of anode, i.e. coating material.

An electric current is passed through the electrolyte for a designated
period of time.

The article used as cathode gets coated with metal used as anode.

Uses and examples :

To protect objects of metals from corresion - Iron or steel articles
are plated with chromium or nickel to prevent rusting.

To improve the look of the object - Brass articled are electroplated
with silver. Silver oranaments are electroplated with gold. Figure
shown above indicates silver plating.

Anodising : Anodising is an application of electrolysis which is used
to make aluminium surface resistant to corrosion and abrasion.Examples
- Kitchen applications like anodised pressure cooker, anodised
nameplates.