Question

What is the decomposition of ${\text{FeS}}{{\text{O}}_{\text{4}}}$?

Answer 1

Hint: A decomposition reaction occurs when a complex material is broken down into two or more simpler substances. A source of energy, such as heat, light, or electricity, is required for most decomposition reactions.

Complete answer:
Decomposition reactions occur all around us, but we are mostly unaware of them. Some common examples of decomposition reactions include: carbonic acid decomposition in soft drinks, water is electrolyzed to produce hydrogen and oxygen.
The main use of ferrous sulphate is as a precursor to other iron compounds. Since it is a reducing agent, it can be used to convert chromate in cement to less volatile ${\text{Cr}}\left( {{\text{III}}} \right)$ compounds.
$FeSO_4$ decomposes into ferric oxide, sulphur dioxide, and sulphur trioxide when heated. This is an illustration of a decomposition reaction.
\[{\text{FeS}}{{\text{O}}_{\text{4}}}\,{\text{ + }}\,{\text{heat}}\,\, \to \,\,{\text{F}}{{\text{e}}_{\text{2}}}{{\text{O}}_{\text{3}}}\,{\text{ + }}\,{\text{S}}{{\text{O}}_{\text{2}}}\,{\text{ + }}\,{\text{S}}{{\text{O}}_{\text{3}}}\]

Additional Information:
Inks were made of ferrous sulphate, the most popular of which was iron gall ink, which was used from the Middle Ages until the end of the eighteenth century.
There are three types of decomposition reaction:
Thermal Decomposition:
Breaking the bonds of the compound requires energy in the form of heat in this reaction. The reaction is usually endothermic, which means that heat is added to it.
Electrolytic Decomposition:
When an electric current is passed into an aqueous solution of the compound, decomposition occurs.
Photo or Photochemical Decomposition:
The compound is decomposed using light (photons) in this reaction.

Note:
Decomposition reactions are not always endothermic. Endothermic and exothermic decomposition reactions are also possible. The latter, on the other hand, is more common than the former. The extraction of metals from their ores is one of the most common uses of decomposition reactions.