QS Study

Based on the Classical concept:

We know that when an oxidizing substance oxidize another substance than that oxidizing substance donate electro-negative atom or radical to the other substances or accepts electro-positive atom or radical. As a result electro-negative part of that substance increases. On the other hand, as the oxidizing substances releases electro­negative part or accept the positive part, it is reduced. Both these changes happen in the same reaction.

It can be explained by the following reaction:

For e.g. If we add stannous chloride solution to the yellow solution of ferric chloride then light green ferrous chloride solution and stannic chloride solution are produced.

2FeCI3 (aq) + SnCI2 (aq) → 2FeCl2(aq) + SnCI4 (aq)

Before the reaction, 3Cl atoms were attached to each iron atom. After the reaction, only two chlorine atoms are attached. That is one negative chlorine atom is released. Therefore, reduction of FeCl3 happened or this reactor on the other hand, before reaction two chlorine atoms where attached with each atom of tin (stannum). Due to the above reaction the number of chlorine attached to tin atom increases to four. That is, oxidation of SnCl2 has taken place. There in this reaction oxidation of one substance and reduction of another substance have taken place; i.e. oxidation-reduction took place simultaneously.

Based on electronic concept:

According to electronic concept of oxidation-reduction, oxidation is such a chemical process in which an atom or ion releases one or more electrons. On the other hand reduction is such a process where an atom or ion accepts electrons. Again the substance which releases electron is known as reducing agents. And the substance which accepts electron is known as oxidizing agent. Therefore, when reducing agent releases electrons oxidizing agent accepts it. As process of releasing electrons is oxidation and process of accepting electron is reduction; then oxidation-reduction occurs together.

Oxidation and reduction are two parts of any reaction which performs gaining and releasing of electron. For e.g. by oxidation reduction process between sodium atom and chlorine atom, NaCl is produced. It can be shown as follow:

Cl2 → 2Cl                     Formation of Cl atom from Cl2 molecule.

2Na → 2Na+ + 2e                    Oxidation (Na is reducing agent)

2Cl + 2e 2Cl                         Reduction (Cl is oxidants)             

2Na + Cl2 → 2(Na+ + Cl) → 2Na+Cl (Oxidation-Reduction)

That is oxidation-reduction takes place simultaneously.