Why are graphite rods used as electrodes in electrolysis?

Electrolysis is a process where electricity is passed
through a solution and this results in the molecules of the solvent and the solute
getting separated into ions. Once ions are formed, the same ions combine with each other
to form a gas or different ions with opposite charges combine with each other resulting
in the formation of different compounds.

Electrodes are
essential for electrolysis as the current enters the solution through one of the
electrodes and returns through the other.

When ions are
formed during electrolysis they can combine with the substance that the electrode is
made of and cause its degradation. For example, if the electrodes used in the
electrolysis of water are made of iron, copper, etc they form hydroxides with the OH-
ions that are created. Electrodes have to be able to resist this corrosion if
electrolysis is to continue over a period of time. Metals like platinum can be used as
electrodes but they are quite expensive. A cheaper alternative that is resistant to
corrosion is graphite.

As graphite conducts electricity and
is resistant to corrosion it is used to make electrodes for
electrolysis.