blue color of copper sulfate solution changes to a pale green or colorless solution when an iron nail is dipped in it because iron is more reactive than copper and displaces it from the solution. This displacement reaction results in the formation of iron sulfate, which is a light green or colorless compound, and the deposition of solid copper on the iron nail.
Here’s a more detailed explanation:
Reactivity:
Iron (Fe) is more reactive than copper (Cu). This means iron is more likely to lose electrons and form positive ions.
Displacement Reaction:
When an iron nail is dipped in copper sulfate solution, iron displaces copper from the solution, forming iron sulfate.
Color Change:
The blue color of the copper sulfate solution is due to the presence of Cu2+ ions. The iron displaces the Cu2+ ions, and the new solution contains Fe2+ ions, which have a pale green or colorless appearance.
Deposition of Copper:
The copper that is displaced from the solution is deposited on the surface of the iron nail as solid copper.
In summary, the reaction is:
Fe(s) + CuSO4(aq) → FeSO4(aq) + Cu(s)
where:
Fe = Iron
CuSO4 = Copper Sulfate (blue solution)
FeSO4 = Iron Sulfate (pale green solution)
Cu = Copper (solid, deposited on the nail)