Question

Why $$\text{KMn}{\text{O}}_{\text{4}}$$ is a self-indicator?

Answer 1

Hint: We have to know that in chemistry two main reactions play a major role. One is the oxidation reaction. Another is the reduction reaction. Oxidation reaction is nothing but addition of oxidation or removal of hydrogen or loss of electrons. Reduction is nothing but addition of hydrogen or removal of oxygen or gain of electrons in the reaction form reactant to product. For oxidation and reduction purposes using some reagents, reagents are called oxidising and reducing agents. The oxidising agent is nothing but the reagent is used for oxidation of reactant to give respect to the product.
The oxidation agent acts as electron acceptor and the reducing agent acts as electron donor. In some cases, oxidation and reduction occur in the same reaction, these kinds of reactions are called redox reactions.
Hydrogen peroxide ($${\text{H}}_{\text{2}}{\text{O}}_{\text{2}}$$), Fenton’s reagent, oxygen ($${\text{O}}_{\text{2}}$$) and ozone ($${\text{O}}_{\text{3}}$$) are examples of common oxidising agent.

Complete answer:
We need to know that the molecular formula of potassium permanganate is $$\text{KMn}{\text{O}}_{\text{4}}$$. Potassium permanganate is one of the oxidising agents in chemistry.
Potassium permanganate is always in the stable form. The reason $$\text{KMn}{\text{O}}_{\text{4}}$$ is also used as a colour indicator in analysis. In acid medium, reduction happens in $$\text{KMn}{\text{O}}_{\text{4}}$$ and it from $$\text{M}{\text{n}}^{\text{2 + }}$$. Hence, the colour of solution changes from pink to brown.
No other indicator is required for once $$\text{KMn}{\text{O}}_{\text{4}}$$ react in the chemical reaction. Because colour changes we will observe the indication. Hence, $$\text{KMn}{\text{O}}_{\text{4}}$$ is a self-indicator.
According to the above discussion, we conclude $$\text{KMn}{\text{O}}_{\text{4}}$$ is a self-indicator.

Note:
We need to remember that the oxidation of primary alcohol gives respect to aldehyde. If the oxidation of secondary alcohol to give respect to ketone product. The oxidation aldehyde gives carboxylic acid. Even oxidation of ketone also gives carboxylic acid. The oxidation of alkane to give primary alcohol and oxidation of alkene give secondary alcohol. The above discussed oxidation process all depends on oxidising agents. Some special oxidising agents are used for direct conversion of alcohol to oxidation. In some oxidation agents are used for direct conversion of alkane to aldehyde. In some cases, alkane directly converts to ketone.