Question

What is a redox reaction with an example?

Answer 1

1. The term ‘redox’ is formed by combining reduction and oxidation. Reduction is the addition of Hydrogen or removal of Oxygen from a substance. In similar sense, oxidation is the addition of Oxygen or removal of Hydrogen from the substance.
2. In terms of electron transfer, reduction is the gain of electrons and oxidation is the loss of electrons. In reduction, oxidation number of an element decreases while in oxidation, the oxidation number increases.
3. Thus, redox reaction can be defined as the reaction in which both oxidation and reduction takes place simultaneously.
4. It involves that there should be loss of electrons by one element and gain by another elements, both which are part of the chemical reaction.
5. Example: ${\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)+\mathrm{Zn}\left(\mathrm{s}\right)\to \mathrm{Cu}\left(\mathrm{s}\right)+{\mathrm{Zn}}^{2+}\left(\mathrm{aq}\right)$
6. In this, ${\mathrm{Cu}}^{2+}$gains two electron to form $\mathrm{Cu}$, thus undergoes reduction.
7. While, $\mathrm{Zn}$ loses two electrons to give its ions, ${\mathrm{Zn}}^{2+}$. Thus, oxidation takes place.
8. Since, both oxidation and reduction are taking place simultaneously, it is a redox reaction.