What is decomposition reaction? Give an example using ferrous sulphate and what will be the ph of the solution?
The decomposition reaction is that reaction in which a single reactant breaks down to give simple products.
2 FeSO4 (s) → Fe2 O3+ SO2 (g)+ SO3 (g)
The ferric oxide is solid while SO2 and SO3 are gases. These gases are acidic hence will turn blue litmus red thus have a pH < 7 in ph scale.