Question: State which of the following chemical reactions will take place or not, giving suitable reason for each:
(a) Zn (s) + CuSO₄ (aq) → ZnSO₄ (aq) + Cu (s)
(b) Fe (s) + ZnSO₄ (aq) → FeSO₄ (aq) + Zn (s)
(c) Zn (s) + FeSO₄ (aq) → ZnSO₄ (aq) + Fe (s) [CBSE, Term 1, Set 1, 2016]
Answer: (b) Fe(s) + ZnSO₄(aq.) → FeSO₄(aq.) + Zn(s)
This chemical reaction is not possible, because Zn is more reactive than Fe, so it cannot be replaced.