Which of the following can undergo a chemical reaction?
(a) MgSO4 + Fe
(b) ZnSO4 + Fe
(c) MgSO4 + Pb
(d) CuSO4 + Fe
Ans. (d)
(a) and (b),
Fe is less reactive than Mg and Zn, so it is impossible to replace them.
No reaction takes place.
(c)
Pb is less reactive than Mg, so it is impossible to replace Mg.
No reaction takes place.
(d)
Fe is more reactive than Cu, so it replaces Cu from CuSO4
Hence reaction takes place.
Therefore option (d) is correct