NCERT Solutions for Class 11 Physics, Chapter 13 - Kinetic Theory

The chapter Kinetic Theory is mainly associated with the movement of particles of gases. Gas doesn’t have a fixed shape or volume and fills up the entire space of the container they are kept in. At a microscopic level, the molecular particles have a high level of mobility and collide with other particles, creating heat. In the CBSE prescribed NCERT Physics for Class 11 Chapter 13 – Kinetic Theory, we learn about the relationship between Pressure, Volume, Temperature and other macroscopic properties of gases, along with the Laws governing them.

Let us take a look at the subtopics of Class 11 Physics, Chapter 13, Kinetic Theory. 

13.1. Introduction

13.2. Molecular Nature of Matter

13.3. Behaviour of Gases

13.4. Kinetic Theory of an Ideal Gas

13.4.1. The Pressure of an Ideal Gas.

13.4.2. Kinetic Interpretation of Temperature.

13.5. Law of Equipartition of Energy

13.6. Specific Heat Capacity

13.6.1. Monoatomic Gases

13.6.2. Diatomic Gases

13.6.3. Polyatomic Gases

13.6.4. Specific Heat Capacity of Solids

13.6.5. Specific Heat Capacity of Water

13.7. Mean Free path

In class 11 Physics, Chapter 13, you will learn:

Section 13.1: In this section, you will learn about the historical development of the Kinetic Theory domain and the works and achievements of important scientists in the past, including Charles Boyle, Isaac Newton, Maxwell Planck, Stefan Boltzmann, and others. We are also provided with a brief overview of the chapter.

Section 13.2: In this section, you will learn that matter is composed of tiny particles called atoms which combine to form molecules. This topic discusses the historical development of our understanding of the atomic model, particularly in the case of gases. We learn about the notable contributions of Kanada (India) and Democritus (Greece) from the ancient ages, including people like John Dalton, Gay Lussac, etc in this field. We are also made aware of Mean Free Path and very important law, especially in the world of Chemistry, that is the Avogadro’s Law.

Section 13.3: In this section, you will learn about the behaviour of gases. The properties of gases are easier to interpret than that of solids or liquids, mainly due to the loosely held gas molecules and the possibility of free movement of these particles. You will also study about Avogadro’s Hypothesis, Boyle’s Law, Charles’ Law and their applications in equations which involve Pressure, Temperature, Volume, Avogadro’s Number, moles etc. We also learn about Ideal Gas – a hypothetical gas that satisfies all the aforesaid postulates.

Section 13.4: In this section, you will learn that we can assume that the molecules in a gas particle are in continuous free motion, rarely colliding with other molecules that might change their velocity or trajectory. Newton’s First Law of Motion is applicable to the particles as long as they are moving in straight lines. The collisions between molecules or between molecules and the container wall may be considered elastic, and the entire system follows the Conservation of Momentum and total Kinetic Energy. In this section, you shall also be learning about Pressure and Temperature from a Kinetic Standpoint – discussed in detail in the two subheadings.

Section 13.5: In this section, you will learn that the Law describes the conservation of total energy through all energy modes in equilibrium and the average energy in each mode roughly being ½ kBT. This is a part of Classical Statistical Mechanics and was first described by Maxwell Planck. For detailed information, please refer to the textbook.

Section 13.6: In this section, you will learn that this part of the chapter is divided into five sub-headings. Accordingly, we learn about the variation of the Specific Heat Capacity in various states of Matter- Monoatomic gases, Diatomic Gases, Polyatomic Gases, Solids, and Water.

Section 13.7: In this section, you will learn that by definition, the Mean Free Path is the average distance travelled by a molecule between two successive collisions. There are equations and derivations to calculate this distance. For more details, please go through Kinetic Theory Class 11 NCERT Solutions.

You can also find Kinetic Theory Class 11 NCERT Solutions Pdf as well as Kinetic Theory Class 11 NCERT Pdf. These will further aid your study of this interesting subject and provide you with enormous confidence.