A student added zinc granules to a freshly prepared ferrous sulphate solution. Mention the changes observed by him. Give a reason for your answer.

A displacement reaction is a reaction in which the atom or a set of atoms is displaced by another atom in a molecule.
Adding zinc granules in freshly prepared ferrous sulphate solution produces zinc sulphate.
The chemical reaction occurs;

$FeS{O}_4\left(aq\right)+Zn\left(s\right)\to ZnS{O}_4\left(aq\right)+Fe\left(s\right)$

The green colour of the solution changes to greenish-white as there is a displacement reaction occurring. Zinc being more reactive than iron displaces it from its salt solution. Hence Fe powder can be observed.