Question

When a mail of iron is added to a solution of copper sulphate,iron (||) suphate and copper metal are formed

Answer 1

Iron has blackish appearance, while Copper is reddish brown. When Iron nail (Ferrum) is dipped in Copper sulphate (CuSO4) there takes reaction between them and coppersulphate change its color from blue to light green. This shows Iron is more reactive than Copper, it can replace Copper from CuSO4.