Overview of Redox Reactions (NEET Chemistry)

Redox Reactions are a fundamental part of the NEET Chemistry syllabus and are asked almost every year in the examination. This chapter focuses on oxidation, reduction, oxidation numbers, and balancing redox reactions. A clear understanding of redox reactions is necessary because it forms the foundation for advanced chapters such as Electrochemistry, Corrosion, Metallurgy, and Chemical Kinetics.

At studentbro.in, Redox Reactions are explained with a formula-based and concept-oriented approach to help NEET aspirants score maximum marks with minimum confusion.

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Introduction to Redox Reactions

A Redox Reaction is a chemical reaction in which oxidation and reduction occur simultaneously. Oxidation is the process of loss of electrons, whereas reduction is the process of gain of electrons.

Example:
Zn + Cu²⁺ → Zn²⁺ + Cu

In this reaction, zinc undergoes oxidation and copper ions undergo reduction. Oxidation and reduction always take place together and cannot occur independently.

Oxidation and Reduction Concepts

Oxidation can be defined as:
• Loss of electrons
• Increase in oxidation number
• Addition of oxygen
• Removal of hydrogen

Reduction can be defined as:
• Gain of electrons
• Decrease in oxidation number
• Removal of oxygen
• Addition of hydrogen

These definitions are frequently tested in NEET conceptual questions.

Oxidizing and Reducing Agents

An oxidizing agent is a substance that causes oxidation of another substance and itself gets reduced.
A reducing agent is a substance that causes reduction of another substance and itself gets oxidized.

Example:
Zn + Cu²⁺ → Zn²⁺ + Cu

• Zinc is the reducing agent
• Copper ion is the oxidizing agent

Oxidation Number (Oxidation State)

Oxidation number is the apparent charge assigned to an atom in a compound or ion.

Important rules of oxidation number:
• Oxidation number of free elements is zero
• Oxidation number of hydrogen is +1 (−1 in metal hydrides)
• Oxidation number of oxygen is −2 (−1 in peroxides)
• Sum of oxidation numbers in a neutral compound is zero
• Sum of oxidation numbers in a polyatomic ion is equal to its charge

These rules are essential for balancing redox reactions.

Identification of Oxidation and Reduction

Increase in oxidation number indicates oxidation.
Decrease in oxidation number indicates reduction.

This concept is widely used in NEET numerical and assertion-reason questions.

Balancing Redox Reactions

Balancing redox reactions is a key topic in NEET Chemistry. There are two main methods used:

Oxidation Number Method

Steps involved:

1. Assign oxidation numbers to all atoms

2. Identify atoms undergoing oxidation and reduction

3. Equalize the increase and decrease in oxidation numbers

4. Balance the remaining atoms and charges

This method is commonly used in reactions occurring in acidic and basic mediums.

Ion-Electron (Half Reaction) Method

Steps involved:

1. Split the redox reaction into oxidation and reduction half-reactions

2. Balance atoms and charges in each half

3. Equalize the number of electrons

4. Add both half-reactions to get the balanced equation

This method is especially useful in electrochemical reactions.

Redox Reactions in Acidic and Basic Medium

In acidic medium:
• Balance oxygen atoms using water
• Balance hydrogen atoms using H⁺ ions

In basic medium:
• Neutralize H⁺ ions by adding OH⁻
• Convert acidic solution into basic medium

Disproportionation Reactions

A disproportionation reaction is one in which the same element undergoes both oxidation and reduction.

Example:
2H₂O₂ → 2H₂O + O₂

In this reaction, oxygen is both oxidized and reduced.

Redox Reactions and Electron Transfer

Redox reactions are fundamentally based on the transfer of electrons.

Oxidation involves loss of electrons.
Reduction involves gain of electrons.

This concept forms the basis of electrochemical cells and batteries.

Importance of Redox Reactions for NEET

• Frequently asked in NEET
• Conceptual and scoring chapter
• Foundation for Electrochemistry
• Important in Inorganic Chemistry

Why Study Redox Reactions from StudentBro?

• NEET-focused formula coverage
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Conclusion

Redox Reactions play a vital role in NEET Chemistry and act as a bridge between physical and inorganic chemistry topics. By mastering oxidation numbers, redox formulas, and balancing techniques, NEET aspirants can easily score high marks from this chapter. Regular revision and practice using studentbro.in will help students build strong concepts and boost their overall NEET performance.