Which of the following can undergo a chemical reaction?
(A) MgSO 4 + Fe
(B) ZnSO 4 + Fe
(C) MgSO 4 + Pb
(D) CuSO 4 + Fe
Answer.:
Let's go through the options
Chemical reactions only occur when the element being displaced is less reactive than the one trying to displace it.
We can know the reactivities of the metals here from the reactivity series .
- Between Mg and Fe, since Fe is less reactive than Mg , it cannot displace Mg from its salt solution.
- Between Zn and Fe, since Fe is less reactive than Zn , it cannot displace Zn from its salt solution.
- Between Mg and Pb, since Pb is less reactive than Mg , it cannot displace Mg from its salt solution.
- Between Cu and Fe, since Fe is more reactive than Cu , it can displace Cu from its salt solution.
So, the correct answer is (d) CuSO 4 + Fe
