Question

On heating ferrous Sulphate decomposition raection takes place. 1.Write the name of gases that are evolved during reaction. 2.Name the residue that is left

Answer 1

Ferrous sulphate is green in colour. On heating, the green crystals are converted into a dirty-yellow anhydrous solid as it loses water of crystallization. When further heated, the anhydrous material releases sulphur dioxide and sulphur trioxide leaving a reddish-brown iron oxide.

2 FeSO4 → Fe2O3 + SO2 + SO3.

Answer 2

Answer: 1. The name of the gases are sulphur dioxide $(SO_2)$ and sulphur trioxide $(SO_3)$.

2. The residue that is left is ferric oxide $(Fe_2O_3)$

Explanation: Ferrous sulphate undergoes decomposition, that is it breaks into two or more than two products on absorption of energy. Two gases are evolved namely sulphur dioxide $(SO_2)$ and sulphur trioxide $(SO_3)$ and a solid ferric oxide $(Fe_2O_3)$ which remains as such and is called as residue.

$2FeSO_4(s)\rightarrow Fe_2O_3(s)+SO_2(g)+SO_3(g)$