Question

When ${S_2}{O_8}^{2 - }$ oxidise \[F{e^{2 + }}\] then product formed is :-
A.${S_2}{O_6}^{2 - }$
B.$S{O_4}^{2 - }$
C.${S_2}{O_8}^{2 - }$
D.$S{O_5}^{2 - }$

Answer 1

Hint:
We can see that ${S_2}{O_8}^{2 - }$ oxidize \[F{e^{2 + }}\] which means ${S_2}{O_8}^{2 - }$ will be reduced and hence acts as a oxidizing agent.

Complete answer:
${S_2}{O_8}^{2 - }\, + 2F{e^{2 + }} \to 2F{e^{3 + \,}} + 2S{O_{^4}}^{2 - }$
In the above reaction we can see that, \[F{e^{2 + }}\] is oxidized to \[F{e^{3 + }}\] and ${S_2}{O_8}^{2 - }$ is reduced to $S{O_{^4}}^{ - 2}$.
From the above reaction we can depict that the above reaction is redox reaction, where ${S_2}{O_8}^{2 - }$ acting as a oxidizing agent which is oxidizing \[F{e^{2 + }}\]to \[F{e^{3 + }}\].
All the redox reactions can be broken down to two processes: the reduction process and the oxidation process.
An oxidation-reduction reaction also known as redox reaction is a chemical reaction in which there is oxidation as well as reduction simultaneously, while the reaction one species is oxidized and other is reduced.
Therefore, Option B is correct.

Additional Information:
In other words, we can understand that the oxidation means loss of electrons from atoms of a substance and hence attaining higher charge whereas reduction means gain of electrons by atoms of a substance and hence obtaining lower charge. And also, in redox reaction transfer of electrons occurs simultaneously.
The substance which gets reduced is known as oxidizing agent because it itself gets reduced to oxidize another species and the substance which gets oxidized is known as reducing agent because it itself gets oxidized by reducing another species.
Redox reactions are of various different types involving decomposition reaction, combination reaction, displacement reaction and disproportionate reactions.
There are various other examples of redox reactions present that are reaction between hydrogen and fluorine, reaction between zinc and copper etc.

Note: We can find the oxidation number of the substance and then be able to know whether the substance gets oxidized or reduced. Please remember atoms in its elemental or native form have oxidation number zero.