Question

What happens in the following? Give reasons for your answer.
A. $Fe + CuS{O_4} \to $
B. $Cu + FeS{O_4} \to $

Answer 1

Hint: In the reactivity series, iron (Fe) is above copper (Cu), hence it will replace the copper in the copper sulphate compound, so the reaction will take place but copper (Cu) is below iron in the reactivity series. It is less reactive than iron, so it won’t replace the iron (Fe) in the compound.

Complete step by step answer:
The reactivity series of metals is shown below:

Metals that are present on top of the other metal in a reactivity series can displace the metal that are present at the bottom from its salt solution.

In the first equation,
 $Fe + CuS{O_4} \to FeS{O_4} + Cu$
Since, Iron (Fe) is present on top of Copper (Cu) in the reactivity series, so it means Iron (Fe) is more reactive than copper (Cu), thus it has a greater tendency to lose electrons and form positive ion, displacing copper ion in copper sulphate solution.
Iron (Fe) will displace copper from its sulphate solution $(CuS{O_4})$ and form Ferrous sulphate $(FeS{O_4})$. This is a typical example of a single displacement reaction where one metal displaces another is the reaction between iron and copper sulphate, Therefore, Fe is more reactive than Cu.
Reactivity of Iron (Fe) > Reactivity of Copper (Cu).

In the second equation,
 $Cu + FeS{O_4} \to $ no reaction
However, since Copper (Cu) is below iron (Fe) in the reactivity series, therefore it is less reactive than iron and therefore unable to displace the ferrous ion $(F{e^{2 + }})$ in ferrous sulphate solution. Hence, the reaction will not occur in this situation.

Note: Iron (Fe) forms 2 types of ions i.e. $F{e^{2 + }}$ and $F{e^{3 + }}$. We will then use the stoichiometric principles to determine which of these ions is formed in the reaction between iron and copper (II) sulphate solution.