Answer :
The reaction in which a single reactant breaks down to give simpler products is known as decomposition reaction. Ferrous sulphate crystals \( {(FeSO_{4} 7H_{2}O)} \)lose water when heated and the colour of the crystals changes. It then decomposes to ferric oxide \({(Fe_{2}O_{3})}\), sulphur dioxide \({(SO_{2})}\) and sulphur trioxide \({(SO_{3})}\) . Ferric oxide is a solid,while sulphur dioxide and sulphur trioxide are gases. \( FeSO_{4}{(s)} \rightarrow Fe_{2}O_{3}{(s)}+SO_{2}{(g)}+SO_{3}{(g)} \)