When zinc is added to a solution of iron(II) sulfate (FeSO₄), the green color of the solution will gradually fade to colorless. This is because zinc, being more reactive than iron, displaces the iron from the sulfate solution, forming zinc sulfate (ZnSO₄) and solid iron. The chemical reaction is: Zn(s) + FeSO₄(aq) → ZnSO₄(aq) + Fe(s).
Elaboration:
Displacement Reaction: The reaction between zinc and iron(II) sulfate is a single displacement reaction. Zinc, being more reactive, takes the place of iron in the sulfate compound.
Color Change: The green color of the iron(II) sulfate solution is due to the presence of the iron ions (Fe²⁺). As the reaction progresses, the iron ions are displaced by zinc, and the zinc sulfate solution formed is colorless.
Solid Iron Formation: Solid iron (Fe) is deposited on the zinc metal as the reaction proceeds.