Which of the following is an oxidation-reduction reaction?
fe2o3 + 3co mc009-1.jpg 2fe + 3co2
cuso4 + 2naoh mc009-2.jpg cu(oh)2 + na2so4
2naoh + h2co3 mc009-3.jpg na2co3 + 2naoh
pb(no3)2 + na2so4 mc009-4.jpg 2nano3 + pbso4

The correct option is: Fe₂O₃ + 3CO → 2Fe + 3CO₂

Explanation:

An oxidation-reduction reaction, also known as the redox reaction, is a chemical reaction in which there is simultaneous transfer of electrons from one species to another.

The species that gains electrons gets reduced. Whereas, species that loses electrons gets oxidized.

Among the given options, only reaction 1 is a redox reaction:

Fe₂O₃ + 3CO → 2Fe + 3CO₂

Reason- In this reaction, iron (Fe) gains electrons and gets reduced from +3 oxidation state in Fe₂O₃ to 0 oxidation state in Fe. Whereas, carbon (C) loses electrons and gets oxidized from +2 oxidation state in CO to +4 oxidation state in CO₂.

Since both the oxidation and reduction reactions are occurring simultaneously.

Therefore, it is an redox reaction.