Question

Role of $KMn{O_4}$ in the given titration can be described as
A. Oxidizing agent
B. Reducing agent
C. Indicator
D. Oxidizing agent and indicator

Answer 1

$KMn{O_4}$ mainly act as an indicator because the permanganate ions have a deep purple color and during this redox titration, $Mn{O_4}^-$ is reduced to the colorless manganese ions ($M{n^{2 + }}$) in the acidic medium.

Complete step by step answer:
In this question we have been asked, in the titration what is the role of $KMn{O_4}$. Let's assume we are titrating $KMn{O_4}$ with oxalic acid. We'll take $KMn{O_4}$ in burette and oxalic acid and sulphuric acid in conical flask and we'll start titrating. When a drop of purple color $KMn{O_4}$ falls in the oxalic acid the purple color of the drops changes to colorless in an acidic medium, and at some point the color of the drop of $KMn{O_4}$ will not change. In this titration $KMn{O_4}$ is acting as a self- indicator and lets understand the reaction between $KMn{O_4}$ and oxalic acid.
As we can see in this reaction, the Oxalic acid is oxidised to carbon dioxide by $KMn{O_4}$ which itself gets reduced to $MnS{O_4}$. Here, $KMn{O_4}$ is acting as an oxidizing agent and as we know in the presence of sulphuric acid, it acts as a strong oxidizing agent. So, in this titration, $KMn{O_4}$ is an oxidizing agent and a self- indicator.
So, the correct option will be D i.e Oxidizing agent and indicator.

Note:
In this titration we add sulphuric acid with oxalic acid because sulphuric acid makes the solution acidic and in acidic solution, $KMn{O_4}$ acts as a strong oxidizing agent.