Why does the colour of copper sulphate solution change when

Why does the colour of copper sulphate solution change when an iron nail is dipped in it?

Answer:

The colour of copper sulphate solution changes because a chemical reaction takes place between iron and copper sulphate.

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Explanation:

• Iron (Fe) is more reactive than copper (Cu).

• When an iron nail is dipped into blue copper sulphate (CuSO₄) solution, iron displaces copper from the solution.

Fe (s) + CuSO_₄ (aq) → FeSO_₄ (aq) + Cu (s)

• The blue colour of copper sulphate fades as pale green iron sulphate is formed.

• You may also see a reddish-brown layer of copper metal deposited on the nail.