Which of the following can undergo a chemical reaction?
MgSO 4 + Fe
ZnSO 4 + Fe
MgSO 2 + Pb
CuSO 4 + Fe
- CuSO 4 + Fe
Explanation : The above reactions are potential Decomposition reactions.
They will proceed only in accordance with the reactivity series .
It is a series of elements arranged in decreasing order of reactivity.
(Most reactive on top, least reactive on bottom)
K > Na > Ca > Mg > Al > Zn > Fe > Pb > H > Cu > Hg > Ag > Au
Since Fe is more reactive than Cu (Fe placed before Cu in reactivity series), Fe displaces Cu .
Other options are incorrect as, based on the positions in the reactivity series, Fe can’t displace Mg, Fe can’t displace Zn and Pb can’t displace Mg.