Which of the following is a displacement reaction?

(i) ZncO₃ (s) → ZnO (s) + CO₂ (g)

(ii) Fe (s) CuSO₄(aq) → FeSO₄(aq) + Cu(s)

(iii) 2H₂ (g) + O₂ (g) →2H2O(I)

(v) CaCO₃ (s) →CaO(s) + CO₂(g)

Question

Question

This question was previously asked in

RRB Group D 30 Aug 2022 Shift 3 Official Paper

Answer 1

The correct answer is (ii).

Key Points

A displacement reaction is a type of chemical reaction.
In a displacement reaction, one element is replaced by another element in a compound.
The more reactive element "displaces" the less reactive element from the compound.

Additional Information

In the reaction Fe (s) CuSO4(aq) → FeSO4(aq) + Cu(s), Fe (Iron) is the replacing element and Cu (Copper) is the replaced element.
The iron ion (Fe2+) is oxidized to Fe3+ in the process, and the copper ion (Cu2+) is reduced to Cu metal.
The reaction between Fe and CuSO4 can be used to extract copper from copper-containing ores
The reaction is an example of single replacement reaction or single displacement reaction.
This reaction is also an oxidation-reduction reaction, as the oxidation state of Iron changes from 0 to +3 and Copper changes from +2 to 0.
The reaction is exothermic and releases heat.
The reaction typically proceeds in the presence of a suitable oxidizing agent, such as H2SO4 or HNO3, which helps to oxidize the iron.