What is oxidation of iron in inorganic chemistry?

The standard reduction potential of iron is -0.44 volt which is less than alkali metals and alkaline earth metals.

Therefore, oxidation of iron metal is not so easy with respect to the above said metals. But oxidation of iron takes place under certain conditions.

Oxidation of iron may occur naturally as well as by artificially. However, oxidation of iron takes place in the presence of air or oxygen and forms ferric oxide, ferrosoferric oxide, ferrate etc compounds.

There is no reaction of iron with dry air. But iron in humid air is oxidized by oxygen of air.

This results in a brown coating on the iron, called rust. Rust is hydrated ferric oxide. Its symbol is Fe2O3.3H2O.

The oxidation number of iron in this compound is +2. That is, the iron has lost two electrons. So the iron has been oxidized. This is natural oxidation of iron.

Oxidation of iron reaction equation

If iron is heated intensely in the presence of air or oxygen it ignites by producing sparks.

In this case also the oxidation of iron occurs. Iron is oxidized by oxygen to produce ferrosoferric oxide [FeO.Fe2O3], in which the mean oxidation number of iron metal atom +8/3.

Hence in this case oxidation of iron has been taken place. The oxidation reaction is shown below.

Under normal conditions iron does not react with alkali. But iron reacts with strong alkalis like NaOH, KOH etc. to produce ferrate compounds.

For examples, sodium ferrate, potassium ferrate etc. The oxidation number of iron in ferrate compounds is +3.

That is, the iron atom has lost three electrons. Thus iron is oxidized indirectly by oxygen.

What Is Oxidation Of Iron In Water?

The most important oxidation reaction of iron is the reaction with steam. Under normal conditions, iron does not react with water.

But when steam is run over red hot iron at a temperature of about 800ᵒC, ferrosoferric oxide and hydrogen are produced.

In this case iron is oxidized and converted into ferrosoferric oxide [FeO.Fe2O3], in which the mean oxidation number of iron metal atom +8/3.

Hence in this case oxidation of iron has been taken place. The oxidation reaction is shown below.