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 answer is

Explanation:

Oxidation-reduction reactions are the reactions in which one compound gets oxidized and another compound gets reduced. These are called as redox reactions.

In oxidation reactions, the element looses its electrons and forms a positive ion. The oxidation state of the element increases in these reactions.

In reduction reactions, the element gains electrons and forms a negative ion., The oxidation state of element gets reduced.

For the given options:

The equation follows:

Oxidation state of Iron on reactant side = +3

Oxidation state of iron on product side = 0

As, the oxidation state of iron is getting reduced. Therefore, it is undergoing reduction reaction.

Oxidation state of carbon on reactant side = +2

Oxidation state of carbon on product side = +4

As, the oxidation state of carbon is increasing. Therefore, it is undergoing oxidation reaction.

This equation is considered as a redox reaction.

The equation follows:

The oxidation state of copper and sodium remains same on both the sides. Hence, it is not considered as a redox reaction.

The equation follows:

The oxidation state of sodium and carbon remains same on both the sides. Hence, it is not considered as a redox reaction.

The equation follows:

The oxidation state of lead and sodium remains same on both the sides. Hence, it is not considered as a redox reaction.

Therefore, the correct answer is

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.