NCERT Solutions for Class 11 Chemistry Chapter 8

Chemistry is related to the transformation of one type of matter into another through chemical reactions. This transformation necessitates a variety of reactions, one of which is the redox reaction. One of the major types of reactions in different biochemical processes is redox reactions. Redox reactions are involved in a variety of phenomena, both physical and biological. Redox reactions are used in a variety of fields including pharmaceuticals, biology, industry, metallurgy, and agriculture. 

Chapter 8 of the Class 11 Chemistry NCERT textbook is titled “Redox Reactions.” Because the entire field of electrochemistry deals with redox reactions, many people consider this chapter to be one of the most important chapters in the CBSE Class 11 Chemistry syllabus. 

NCERT Solutions for Class 11 Chemistry Chapter 8 – Redox Reactions

Before delving into the details of NCERT Solutions Class 11 Chemistry Chapter 8, students should familiarise themselves with the topics covered in Class 11 Chemistry Chapter 8 to get a sense of the chapter’s constituent topics.

8.1 Classical Idea of Redox Reactions – Oxidation and Reduction Reactions

Redox reactions are chemical reactions in which the reactants are simultaneously oxidised and reduced. The term ‘redox’ refers to the reduction-oxidation process. In this type of reaction, one chemical species gains electrons while the other loses electrons. In simpler words, this reaction involves the transfer of electrons. The species that loses electrons becomes oxidised, while the species that gains electrons becomes reduced.

8.2 Redox Reactions in terms of Electron Transfer Reactions

Half-reactions that involve the loss of electrons are referred to as oxidation reactions in this topic. Reduction reactions, on the other hand, are the other half-reactions that involve the gain of electrons.

8.2.1 Competitive Electron Transfer Reactions

These reactions are indirect redox reactions which take place in different vessels. For instance, Zn gives electrons to Cu, and Cu gives electrons to Silver, and so on.

8.3 Oxidation Number 

This number denotes the oxidation state of an element in a compound determined by a set of rules based on the assumption that in a covalent bond, an electron pair belongs entirely to a more electronegative element. 

8.3.1 Types of Redox Reactions

Combination Reactions, Displacement Reactions, Decomposition Reactions, and Disproportionation Reactions are the types of redox reactions covered in this section.

8.3.2 Balancing of Redox Reactions

Two methods are used to balance chemical equations for redox processes. The first method is based on the oxidation number of the reducing and oxidising agents changing, while the second method is based on splitting the redox reaction into two half-reactions, one involving oxidation and the other involving reduction. This section of the chapter teaches students the steps involved in the two methods.

8.3.3 Redox Reactions as the Basis for Titrations

Titration is the process of allowing two reagents’ solutions to react with one another. The goal of these titrations is to determine the exact amount of acid (or base) present in a given solution by reacting it with a standard base solution (or an acid). A redox titration occurs when oxidation-reduction reactions occur in a titration method. During the chemical reaction, electrons are transferred to the reacting ions present in the aqueous solutions using this technique. This is further divided into subcategories based on the reagent used in the redox titration.

8.3.4 Limitations of Concept of Oxidation Number

Here are the limitations of the concept of oxidation number.

• The result of using the concept of oxidation state frequently differs from the result obtained using the classical approach.
• Furthermore, using the concept of oxidation number to classify some reactions as redox reactions is difficult.

8.4 Redox Reactions and Electrode Processes

This topic depicts an experiment that students can perform to learn about redox couples.

Redox reactions occur when reduction and oxidation reactions take place at the same time. The discussions in this chapter begin with a fundamental understanding of redox reactions, as well as learning the fundamental definitions and terminologies. The redox mechanisms are then explored. Finally, using redox reactions and reactions at the electrode to balance chemical equations is discussed. 

Access NCERT Solutions for Class 11 Chemistry Chapter 8 – Redox reactions 

Solutions 

NCERT Solutions for Class 11 Chemistry Chapter 8 – Redox Reactions 

Students can use the link given below and access Redox Reaction NCERT Solutions for this chapter. 

Redox Reactions 

The permutations and combinations of oxidation and reduction reactions are discussed in Chapter 8. There are a variety of biological and physical phenomena that are related to redox reactions. Reactions are also used in the fields of biology, pharmaceuticals, metallurgy, industry, and agriculture. After studying this unit, students will be able to recognise redox reactions as reactions in which both reduction and oxidation occur at the same time.

The terms reduction, oxidation, oxidant, and reductant will all be covered in the Class 11 Chemistry Chapter 8 NCERT. Furthermore, using the electron transfer process, students will be able to explain the mechanism of redox reactions. They will also use the concept of oxidation number to identify a reaction’s reductant and oxidation. As a result, the redox reaction will be divided into four categories: combination, displacement, decomposition, and disproportionation. You’ll also propose a ranking of the different oxidants and reductants. Using the half-reaction method and the oxidation number, you will learn how to balance chemical equations. 

Students will learn about the ideas of redox reactions and oxidation reactions in this chapter. They will also learn about competitive electron transfer reactions, electron transfer reach, oxidation number, redox reaction types, and redox reaction balancing. 

Types of Redox Reactions

There are four types of redox reactions:

1. Decomposition Reaction – The reaction involves breaking down a compound into different compounds.
2. Combination Reaction – Opposite of decomposition reaction, it involves combination of two compounds forming a single compound in the form of A+B  → AB
3. Displacement Reaction – In displacement reaction, an ion or atom in a compound is replaced by an ion or atom in another element. It is represented in the form of X + YZ  → XZ + Y. The displacement reaction is further categorised into – Metal Displacement Reaction and Non-metal Displacement Reaction.
4. Disproportionation Reaction – It is the reaction in which a single reactant is oxidised and reduced.

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Students in class 11 can use Extramarks’ Class 11 Chemistry Chapter 8 NCERT solutions for exam preparation and revision. The solutions are prepared by subject matter experts in accordance with CBSE guidelines and the prescribed syllabus. Every answer in the NCERT Class 11 Chemistry solution is detailed and comprehensive. Extramarks offers NCERT Solutions Class 11 Chemistry Chapter 8 to registered students.

The NCERT Solutions by Extramarks are the result of extensive research, making them one of the best reference materials available to students. These give a step-by-step explanation of all of the questions in the textbooks. Students can use them to help them with their home assignments and board and competitive exam preparation.

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Our experts have prepared the NCERT Solution Class 11 Chemistry, which presents the answers in the simplest way possible to ensure a better understanding of the subject.

These solutions NCERT Solutions Class 11 Chemistry have been organised chapter-by-chapter and exercise-by-exercise so that students can quickly find the answers to the textbook questions. We have ensured that students gain a thorough understanding of the subject and achieve higher exam results. Apart from these, Extramarks provides sample papers, past  years’ question papers, important questions, and much more for students to practise and master the subject.

Solved Examples on Redox reaction Class 11 NCERT Solutions

Solutions

Que. Write the formulas for the following substances:

(a) Chromium (III) oxide

(b) Mercury (II) chloride

(c) Nickel (II) sulphate

(d) Tin (IV) oxide

Ans. (a) Cr2 O3

(b) HgCl2

(c) NiSO4

(d) SnO2

Que. AgF2 is an unstable compound. However, once formed, it acts as a potent oxidising agent. Why?

Ans. In AgF2, the oxidation state of Ag is +2. This +2, on the other hand, is an Ag state that is unstable. Silver accepts an electron to form Ag+ whenever AgF2 is formed. It reduces Ag’s oxidation state from +2 to +1, which is a more stable state. AgF2 becomes a powerful oxidising agent as a result of this.

Related Questions

Solutions 

Que. Which of the following statements about the oxidation states of the elements is false?

A.Sulphur +6 to −2

B.Carbon +4 to −4

C.Chlorine +7 to −1

D.Nitrogen +3 to −1

Ans. Nitrogen +3 to −1

1. Q) When the colour of chromium (VI) changes from orange to green, it indicates the presence of a:

A.Reducing agent

B.Oxidizing agent

C.Reagent

D.Drying agent

Ans. Reducing agent

1. Q) Select the appropriate statement(s):
2. A) In an acidic medium, 1 mole of MnO4– ion can oxidise 5 moles of Fe2+
3. B) In an acidic medium, 1 mole of Cr2O72- ion can oxidise 6 moles of Fe2+
4. C) In an acidic medium, 1 mole of Cu2S can be oxidised by 16 moles of MnO4
5. D) In an acidic medium, 1 mole of Cu2S can be oxidised by 133 moles of Cr2O72-

Ans. The following statements are correct:

 In an acidic medium, 1 mole of MnO4– ion can oxidise 5 moles of Fe2+ ion.

In an acidic medium, 1 mole of Cr2O72- ion can oxidise 6 moles of Fe2+ ions.

1. Q) Write each reactant that undergoes oxidation or reduction, as well as the type of reaction, in the following reaction.

BaSO4 + 4C → BaS + 4CO

1. Q) When an aqueous solution of hydrogen sulphide and sulphur dioxide is mixed, the result is:

(A)- sulphur and water

(B)- hydrogen peroxide and sulphur

(C)- sulphur trioxide and water

(D)- hydrogen and sulphurous dioxide

Ans. Sulphur and water

1. Q) When Cl2 reacts with NaOH in a cold environment, the chlorine oxidation number changes from 0 to 
2. A) -1 
3. B) +1 
4. C) -2 
5. D) +2

Ans. Correct options are:A) -1 and B)+1.

1. Q) When heated, which of the following does not produce oxygen?

1) (NH4)2Cr2O7

2) KClO3

3) NaNO3

4) K2Cr2O7

Ans. (NH4)2Cr2O7