Answer: When an iron nail immersed in the solution of copper sulphate than iron displaces copper from the solution of copper sulphate because iron is more reactive than copper. Therefore copper sulphate solution colour changes from blue to pale green. CuSO4 (aq) + Fe (s) → FeSO4 (aq) + Cu (s) In this reaction following two processes take place: The reaction can be double displacement reaction as well as redox reaction (oxidation and reduction both takes place simultaneously). ExplanationWhen an iron nail is dipped in copper sulphate solution, a brown coating of copper is formed in the surface of iron and the colour of copper sulphate solution changes from blue to pale green. The reaction shows that iron is more reactive than copper because it displaces copper from the copper sulphate solution. The iron passes into the solution as Fe (II) forming the ferrous sulphate solution.
Text Solution Solution : (a) When an iron nail is immersed in the aqueous solution of copper sulphate, a brown coating of copper is developed over iron and the blue copper sulphate solution becomes pale green since iron is more reactive than copper.<br> (b) Fe(s) + CuSO4(aq) → FeSO4(aq) + Cu(s)<br> (c) It is a chemical change and the above reaction is a displacement reaction. |