Question

Write the chwmical reaction.
iron dust are added to aq. Soln. CuSO4.

Answer 1

As iron is above copper in the reactivity series, it displaces the copper in copper sulphate sol. Reddish brown deposits of copper can be seen at the bottom test tube.

Fe+CuSO4—→Cu+FeSO4

This reaction is an example for displacement reaction.

Answer 2

Iron is more reactive than Copper. So it will displace the sulphate ion from copper sulphate.

$Fe(s) + CuSO_4(aq) = FeSO_4(aq) + Cu(s)$

Iron sulphate is stays in the solution I'm aqueous form and copper is precipitated.