Question

Identify the type of chemical reaction taking place: On heating green color ferrous sulfate crystals, a reddish-brown solid is left and the smell of gas has the odor of burning Sulphur is experienced.

Answer 1

1. On heating, green-coloured ferrous sulphate crystals$\left({\mathrm{FeSO}}_4\right)$, a reddish-brown solid called Ferric oxide/Iron (III) oxide $\left({\mathrm{Fe}}_2{\mathrm{O}}_3\right)$ is formed and a small of gas having the odour of burning Sulphur is experienced.
2. The chemical reaction can be written as:

$\underset{Green\mathrm{c}olorsolid}{\underbrace{\underset{\mathrm{Ferrous}\mathrm{sulphate}}{{\mathrm{FeSO}}_4\left(\mathrm{s}\right)}}}+\mathrm{Heat}(∆)\to \underset{\mathrm{Red}\mathrm{brown}\mathrm{solid}}{\underbrace{\underset{\mathrm{Iron}\left(\mathrm{III}\right)\mathrm{oxide}}{{\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)}}}+\underset{\mathrm{Sulphur}\mathrm{trioxide}}{{\mathrm{SO}}_3\left(\mathrm{g}\right)}+\underset{\mathrm{Sulphur}\mathrm{dioxide}}{{\mathrm{SO}}_2\left(\mathrm{g}\right)}$

3. Here, we can see that ${\mathrm{FeSO}}_4$ is decomposed to form products like${\mathrm{Fe}}_2{\mathrm{O}}_3$, ${\mathrm{SO}}_3$, and ${\mathrm{SO}}_2$.

4. Thermal decomposition is the reaction in which substances are broken down due to heat.

5. This is a type of thermal decomposition reaction as heat energy is involved to separate its constituent elements.