Redox Reactions: Overview, Questions, Preparation

Redox titration is based between the titrant and the analyte on an oxidation-reduction response. Identifying the concentration of unknown analytes is one of the most common laboratory methods. The form of the related titration curve must be obtained for determining redox titrations. In these types of titration, instead of monitoring the concentration of the reacting species, it proves convenient to monitor the reaction potential.

A redox reaction involves both oxidation and reduction. Below are details of the oxidation and reduction process.

Oxidation	Reduction
A material that has undergone oxidation is outlined in the following points:	The reduction of a substance will occur via:
The oxygen addition. The hydrogen that was bound to the organisms was extracted. The loss/donation of electrons. A rise in the state of oxidation is displayed by the material.	The hydrogen extension. The elimination of oxygen. The adoption of electrons. A reduction in the total state of oxidation.

It should also be noted that redox titrations require an electron transfer between the analyte & the titrant in question. The preparation of a solution of iodine with a reducing agent is an instance of redox titration. Using an indicator (starch), the endpoint of this titration is observed.

Redox Titration Illustration (Potassium Permanganate and Oxalic Acid)

The analyte is oxalic acid in the titration, and the titrant is permanganate of potassium. Oxalic acid acts as an agent of reduction, and KMnO4 acts as an agent of oxidation. Because the reaction happens in an acidic medium, the permanganate ion’s oxidising capacity is enhanced.

Combination Reaction

These reactions are the opposite of the decomposition reaction and therefore require the combination of two compounds that form a single compound in the form of A+B and AB. For instance:

H2 + Cl2 → 2HClC+O2→CO2

Displacement Reaction

In this form of reaction, an atom or an ion in a compound is substituted by an atom or an ion in another product. It can be interpreted in the form of X + YZ XZ + Y. 

Metal Substitution Reaction

In this form of reaction, the metal contained in the compound is substituted by another metal. These forms of reactions are used in metallurgical processes where pure metals are produced from their ores. For instance: 

CuSO4+Zn→Cu+ZnSO4

Non-Metal Displacement Reaction

In this form of reaction, we may observe hydrogen displacement and often unusual reactions involving oxygen displacement.

Disproportionate Reaction

Reactions under which a single reactant is oxidised and reduced are classified as disproportion reactions. For instance: 

P4 + 3NaOH + 3H2O → 3NaH2PO2 + PH3

Redox Titration in Class 11

Class 11 has a basic study of the redox titration under the chapter ‘Redox Reaction’. The weightage of this topic is 4 marks.

Redox Titration in Class 12

In Class 12, There are a number of chapters covering the concept of redox titration. Of these, an important chapter is ‘P-block’.

Illustrated Examples

1. Explain redox titration with an example.

The treatment of an iodine solution with a reducing agent to generate iodide using an indicator to help know the endpoint is a typical example of redox titration.

2. Why is KMnO4 a self-indicator?

Solutions for KMnO4 are dark purple. When used as a titrant, the solution has a lasting pink shade as soon as the endpoint is hit and the KMnO4 is in excess (provided that the solution is initially colourless). KMnO4 thus functions as an indicator of its own.

3. What's the distinction between a titration of an acid-base and redox titration?

In an acid-base titration, acids and bases are concerned. Redox titrations are titrations where a redox reaction takes place.

Q. What is the purpose of redox titration?

Q. What is the principle of redox titration?

Q. Why is an indicator not used in redox titration?

Q. What's the method of redox titration?

Q. What titration results in oxidation-reduction?