Question

Which of the following can undergo a chemical reaction?

• A. ${\mathrm{MgSO}}_4+\mathrm{Fe}$
• B. ${\mathrm{ZnSO}}_4+\mathrm{Fe}$
• C. ${\mathrm{MgSO}}_4+\mathrm{Pb}$
• D. ${\mathrm{CuSO}}_4+\mathrm{Fe}$

Answer 1

The correct option is D

${\mathrm{CuSO}}_4+\mathrm{Fe}$

Explanation for correct option:

D. ${\mathrm{CuSO}}_4+\mathrm{Fe}$

Displacement Reaction:

• When a more reactive metal displaces a lesser reactive metal from its salt, is known as a displacement reaction.
• As per the reactivity series of metal, metal placed above is regarded as more reactive and it can displace a metal that is placed below it.
• Iron displaces copper from its solution as it is more reactive than copper according to the reactivity series.

• Iron is more reactive than copper. Thus it displaces copper in the reaction to form Ferrous sulfate$\left({\mathrm{FeSO}}_4\right)$.
• This is an example of a Metal displacement reaction.

Explanation for incorrect options:

A. $\mathrm{Mg}$ is more reactive than $\mathrm{Fe}$. Thus, no reaction will take place.

B. $\mathrm{Zn}$ is more reactive than $\mathrm{Cu}$. Thus, no reaction will take place.

C. $\mathrm{Mg}$ is more reactive than $\mathrm{Pb}$. Thus, no reaction will take place.

Hence, the correct option is D i.e. ${\mathrm{CuSO}}_4+\mathrm{Fe}$.