Which of the following changes requires an oxidizing agent?
o2 yields 2o2-
so3 yields so42-
2f- yields f2
mno2 yields mn2+

Answer : The correct option is,

Explanation :

Oxidation reaction : It is defined as the reaction in which a substance looses its electrons. In the oxidation reaction, the oxidation state of an element increases. Or we can say that in oxidation, the loss of electrons takes place.

Oxidizing agent : It is defined as the substance which has ability to oxidize the other substances by gaining electrons.

Reduction reaction : It is defined as the reaction in which a substance gains electrons. In the reduction reaction, the oxidation state of an element decreases. Or we can say that in reduction, the gain of electrons takes place.

Reducing agent : It is defined as the substance which has ability to reduce the other substances by losing electrons.

From the given options, we conclude that

(1)

(2)

(3)

The reaction 1, 2 and 3 shows the reduction reaction. So, it requires a reducing agent.

(4)

The reaction 4 shows the oxidation reaction. Therefore, it requires an oxidizing agent.

Therefore, the correct option is,