1. The iron nail becomes coated with copper:
* Iron is more reactive than copper. This means that iron atoms can displace copper ions from the solution.
* Iron atoms lose electrons and become iron(II) ions (Fe²⁺). These ions then dissolve into the solution.
* Copper ions (Cu²⁺) from the solution gain electrons and become copper atoms, which deposit onto the surface of the iron nail.
2. The blue color of the copper sulphate solution fades:
* Copper sulphate solution is blue due to the presence of copper(II) ions (Cu²⁺).
* As copper ions are consumed in the reaction, the blue color gradually fades.
3. The solution may turn greenish:
* Iron(II) ions (Fe²⁺) dissolved in the solution can react with sulphate ions (SO₄²⁻) to form iron(II) sulphate, which has a greenish color.
The overall chemical reaction can be represented as:
Fe(s) + CuSO₄(aq) → FeSO₄(aq) + Cu(s)
In summary:
* Iron displaces copper from the solution, coating the nail with copper.
* The blue color of the copper sulphate solution fades.
* The solution may turn greenish due to the formation of iron(II) sulphate.
This reaction is an example of a single displacement reaction, where a more reactive metal displaces a less reactive metal from its compound.
