Examples: Redox Reactions

Introduction

Redox reactions are also referred to as oxidation-reduction chemical reactions, where oxidation states of reactants change frequently. The term ‘redox,’ when expanded, becomes reduction-oxidation. All types of redox reactions are divided down into two major types of reactions. These are reduction and oxidation reactions.

In a redox reaction, the oxidation and reduction reactions always occur at the same time. The oxidizing agent is the substance that is being reduced in a chemical process, while the reducing agent is the substance that is being oxidized.

What are Redox Reactions?

Talking about the definition of a redox reaction, it refers to the chemical reaction in which electrons are relocated between two active reactants. This transfer of electrons can be identified by observing the changes in the oxidation states of the reacting species.

Oxidizing agents are electron-accepting entities that tend to suffer a reduction in redox processes. A reducing agent is an electron-donating species that tend to hand over electrons. Oxidation is a common occurrence in several species. Any redox process can be decomposed into two half-reactions, namely the oxidation half-reaction and the reduction half-reaction.

Before we give an example of a redox reaction, let’s discuss the types of redox reactions:

Types of Redox Reactions

The different types of redox reactions are:

• Decomposition Reaction
• Combination Reaction
• Displacement Reaction
• Disproportionation Reactions

1. Decomposition Reaction

The breakdown of a molecule into other compounds is what this reaction entails. Some examples of these types of reactions:

2NaH → 2Na + H2

2H2O → 2H2 + O2

Na2CO3 → Na2O + CO2

All of the reactions mentioned above lead to the breakdown of smaller chemical compounds in AB → A + B.

2. Combination Reaction

These reactions are the inverse of decomposition processes in that they combine two chemicals to generate a single compound with the formula A + B → AB. Consider the following scenario:

H2 + Cl2 → 2HCl

C + O2 → CO2

4 Fe + 3O2 → 2Fe2O3

3. Displacement Reaction

An atom or an ion of a compound is replaced by an atom or an ion of another element in this reaction. It can be represented as X + YZ → XZ + Y. Displacement reactions can also be divided into two types.

• Metal displacement Reaction
• Non-metal displacement Reaction

4. Metal Displacement

Another metal displaces a metal present in the compound in this reaction. When pure metals are extracted from their ores in metallurgical procedures, several types of reactions are used.

For example, CuSO4 + Zn → Cu + ZnSO4

• Non-Metal Displacement

We can detect a hydrogen displacement reaction in this type of reaction and rare oxygen displacement events.

2K (s) + 2H2O (l) →KOH (aq) + H2 (g)

• Disproportionation Reactions

Disproportionation reactions are those that involve only one reactant being oxidized and reduced.

For example: P4 + 3NaOH + 3H2O → 3NaH2PO2 + PH3

Examples of Redox Reactions

There are over 20 examples of redox reactions, but we will focus on a few significant examples of redox reactions and their oxidation and reduction half-reactions.

Example 1: Reaction Between Hydrogen and Fluorine

The hydrogen in the reaction between hydrogen and fluorine is oxidized, while the fluorine is reduced. The following is an example of a reaction.

H2 + F2 → 2HF

The half-reaction of oxidation is: H2 → 2H+ + 2e–

The half-reaction of reduction is: F2 + 2e– → 2F–

After that, the hydrogen and fluorine ions unite to form hydrogen fluoride.

Example 2: Reaction Between Zinc and Copper

We’ll give an example of a redox reaction that shows the reaction between zinc and copper.  

This is a metal displacement reaction in which zinc displaces the Cu2+ion in a copper sulfate solution to produce copper metal, as seen in the reaction below.

Zn (s) + CuSO4 (aq) → ZnSO4 (aq) + Cu (s)

The oxidation half-reaction can be signified as Zn → Zn2+ + 2e–

The reduction half-reaction can be signified as Cu2+ + 2e– → Cu

Example 3: Reaction between Iron and Hydrogen Peroxide

This is one of the biggest examples of redox reactions!

When an acid is present, hydrogen peroxide oxidizes Fe2+ to Fe3+. 

Oxidation half-reaction: Fe2+ → Fe3+ + e–

Reduction half-reaction: H2O2 + 2e– → 2 OH–

As a result, the hydroxide ion generated by hydrogen peroxide reduction joins with the proton provided by the acidic medium to form water.

Oxidation and Reduction Reaction

Let’s look at oxidation and reduction reactions separately to comprehend redox reactions better.

What is Oxidation Reaction?

The addition of oxygen or the more electronegative element to a compound or the removal of hydrogen or the more electropositive element from a substance is called an oxidation reaction, according to one definition.

Oxidizing and Reducing Agents

• An oxidizing agent is a material (atom, ion, or molecule) that acquires electrons and is thereby reduced to a low valency state.
• A reducing agent is a chemical that loses electrons and hence oxidizes to a higher valency state.

Important Oxidizing Agents

• Electronegative components make up molecules. For example, O2, O3, and X2 (halogens)
• Compounds that include an element in a more oxidized form. For example, KMnO4, K2Cr2O7, HNO3, and KClO3
• Metal and non-metal oxides. MgO, CuO, CrO3, P4O10, etc.
• Fluorine is the most powerful oxidizer.

What is Reduction Reaction?

Reduction reactions, like oxidation events, are defined as electron gains. During a chemical process, any material that acquires an electron is reduced.

The reduction reaction is defined as the addition of hydrogen or a more electropositive element to a substance or the removal of a more electronegative element or oxygen.

Common Uses of Redox Reaction in Everyday Life

Redox reactions have a wide range of uses in industry and everyday life, as well as several benefits and side effects.

• Food and oxygen are converted to carbon dioxide and water (cellular respiration, including glycolysis)

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy

• Battery functionality in all electrical gadgets
• Photosynthesis — the conversion of carbon dioxide to sugars and of water to molecular oxygen.

6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2

• Combustion of organic materials and hydrocarbons in fossil fuels
• Ore extraction from minerals
• Electroplating
• Shooting and developing a photographic film
• Decolorization and bleaching
• Corrosion
• Breathalyzer

Conclusion 

In a redox reaction, the oxidation and reduction reactions always co-occur simultaneously. The oxidizing agent is the substance that is being reduced in a chemical process, while the reducing agent is the substance that is being oxidized. There are four types of redox reactions: decomposition reaction, combination reaction, displacement reaction, disproportionation reactions. In the above article, we have discussed each of these in detail with examples. In addition, we also discussed the common uses of redox reactions to help better understand.