A visible change is observed when a strip of iron is placed in an aqueous solution of

When a strip of iron is placed in an aqueous solution of CuSO₄, a visible change is observed. This is because copper ions in the CuSO₄ solution gain electrons from the iron strip and are reduced to metallic copper, which is deposited on the iron strip. At the same time, iron atoms on the strip lose electrons and are oxidized to iron(II) ions, which dissolve in the solution. The overall reaction is: Fe(s) + CuSO₄(aq) → FeSO₄(aq) + Cu(s) The visible change observed is the deposition of metallic copper on the iron strip, which appears as a reddish-brown coating. This process is known as a displacement reaction, where a more reactive metal (in this case, iron) displaces a less reactive metal (copper) from its salt solution.