Question

Which of the following changes requires an oxidizing agent?

O2 yields 2O2-
SO3 yields SO42-
2F- yields F2
MnO2 yields Mn2+

Answer 1

2F⁻ → F₂ + 2e⁻

(mainly electrochemical oxidation)

Answer 2

Answer : The correct option is,
`2F^-\rightarrow F_2+2e^-`

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)
`O_2+4e^-\rightarrow 2O^(2-)`

(2)
`SO_3+H_2O\rightarrow SO_4^(2-)+2H^+`

(3)
`MnO_2+4H^++2e^-\rightarrow Mn^(2+)+2H_2O`

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

(4)
`2F^-\rightarrow F_2+2e^-`

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

Therefore, the correct option is,
`2F^-\rightarrow F_2+2e^-`