Question

Name the products formed on strongly heating ferrous sulphate crystals. What type of chemical reaction occurs in this change?

Answer 1

Hint: We know the molecular formula of ferrous sulphate is $FeS{O_4}.7{H_2}O$and on heating, it loses its water molecule to form anhydrous ferrous sulphate molecule. So the color of the ferrous sulphate crystal changes from light green to white.

Complete step by step answer:
First, we understand the decomposition reaction.
If a compound breaks down to two or more substances then it is a decomposition reaction. The general equation for the reaction is,
$AB\xrightarrow{{}}A + B$
Now we see the double decomposition reaction.
The reaction in which the two reactants interchange their positive and negative ions and form a new compound is called a double decomposition reaction. The general equation of the reaction is,
$AB + CD\xrightarrow{{}}AD + CB$
On heating, ferrous sulphate crystals lose water and it forms anhydrous ferrous sulphate so the color of the crystal changes from light green to white and on further heating anhydrous ferrous sulphate decomposes to give ferric oxide, sulphur dioxide, and sulphur trioxide.
$2FeS{O_4}\xrightarrow{\Delta }F{e_2}{O_3} + S{O_2} + S{O_3}$
In the single reaction ferrous sulphate decomposed into three products.
We can conclude it is a decomposition reaction.

Additional Information: There are three types of decomposition reactions.
Thermal decomposition reaction: The decomposition reaction which is activated by the thermal energy is defined as a thermal decomposition reaction. The decomposition of Calcium Carbonate is a suitable example of a thermal decomposition reaction.
$CaC{O_3}\xrightarrow{\Delta }CaO + C{O_2}$
Electrolytic decomposition reaction: The decomposition reaction which is activated by the electrical energy is defined as an electrolytic decomposition reaction. The electrolysis of water is a suitable example of an electrolytic decomposition reaction.
$2{H_2}O\xrightarrow{{}}2{H_2} + {O_2}$
Photolytic decomposition reaction: The decomposition reaction in reactants broken down to simpler substances by absorbing energy from photons is defined as a photolytic decomposition reaction. The decomposition of ozone is a suitable example of a photolytic decomposition reaction.
${O_3} + h\gamma \xrightarrow{{}}{O_2} + {O^.}$

Note:
We must know that the decomposition of ferrous sulphate to ferric oxide is a thermal decomposition reaction and the reaction is endothermic because heat energy is supplied to break the bonds in the compound.