Best Offline Course for JEE 2026 | Get IIT in First Attempt | Limited Seats

NCERT Solutions Class 11 Chemistry Chapter 1 Some Basic Concepts of Chemistry - PDF Download

JEE Mains & Advanced

NCERT Solutions Class 11 Chemistry - Chapter 1 deals with some basic concepts of chemistry.  Class 11 Chemistry - Chapter 1 contains a number of questions in the exercise of the chapter.  eSaral’s experts in Chemistry explain the answers of all questions. We provide you with some basic concepts of Chemistry class 11 NCERT solutions to make your study simple and fun. You can also download NCERT solution for class 11, Chemistry chapter 1 free PDF from eSaral's website to help you complete the syllabus correctly and score maximum marks in your exams. 

After studying this chapter, Some basic concepts of chemistry, you will be able to understand-

  • The role of India in the development of chemistry

  • The role of chemistry in different spheres of life

  • The properties of three states of matter

  • Classification of different substances into elements, compounds and mixtures

  • Uses of scientific notation, determine significant figures, differentiate between precision and accuracy, define SI base units, convert physical quantities from one system of units to another, 

  • Various laws of chemistry, appreciate significance of atomic, average atomic, molecular and formula mass.

  • Terms – mole and molar mass, 

  • The mass percentage of component elements constituting a compound, determine empirical formula and molecular formula for a compound from the experimental data

NCERT Solutions for Class 11 Chemistry Chapter 1 Subtopics 

Section Name

Topic Name

        1

Some Basic Concepts of Chemistry

       1.1

Importance of Chemistry

       1.2

Nature of Matter

       1.3

Properties of Matter and their Measurement

       1.4

Uncertainty in Measurement

       1.5

Laws of Chemical Combination

       1.6

Dalton’s Atomic Theory

       1.7

Atomic and Molecular Masses

       1.8

Mole Concept and Molar Masses

      1.9

Percentage Composition

      1.10

Stoichiometry and Stoichiometric Calculations

NCERT Solutions for Class 11 Chemistry Chapter 1 Subtopics  

1.1 Importance of Chemistry: Chemistry is a fundamental field of science and is often associated with other areas of science. The principles of chemistry can be applied to a variety of topics, including the weather, the functioning of the brain, the operation of a computer, the production of chemicals, the production of fertilizers, alkali, acid, salt, dye, polymer, drugs, soap, detergent, metals, and alloys, as well as new materials.

1.2 Nature of Matter : You’ve heard the term matter before in your previous classes. Anything that has mass and takes up space is matter. Everything around us, like a book, a pen, a pencil, the water, the air, all living things, etc. Is made of matter. In this section, we will discuss different characteristics of the states of matter.

1.3 Properties of Matter and their Measurement: in this section, following subtopics will be discussed.

         1.3.1  Physical and chemical properties

         1.3.2  measurement of physical properties

         1.3.3  The international system of units (SI)

         1.3.4  Mass and Weight

         1.3.5  Volume

         1.3.6  Density

1.4   Uncertainty in Measurement: 
Many times in the field of chemistry, we have to deal with both experimental data and theoretical calculations. Fortunately, there are ways to deal with these numbers in a convenient way and to present the data in a realistic way to the extent possible. Following ideas will be discussed in detail in this section.

  • Scientific Notation

  • Significant figures

  • Dimensional Analysis

1.5  Laws of Chemical Combination:
The five fundamental laws govern how elements are combined to form compounds. In this section, these five fundamental laws will be discussed in detail.

  • Law of Conservation of Mass

  • Law of Definite Properties

  • Law of Multiple Proportions

  • Gay Lussac’s Law of Gaseous Volumes

  • Avogadro’s Law

1.6 Dalton’s Atomic Theory: 
Dalton published his ‘New System of Chemical Philosophy’ in 1808. In it, he proposed the following:

  • Matter is made up of atoms that are indivisible

  • Each atom of a given element has the same properties, including the same mass

  • Atoms of different elements vary in mass

  • Compounds are created when atoms of different elements come together in a fixed ratio

  • Chemical reactions involve the rearrangement of atoms

  • These are not created or destroyed in a chemical reaction

1.7 Atomic and Molecular Masses: Now that we have a basic understanding of atoms and molecules, let’s take a closer look at what we mean by atomic and molecular mass.
Following terms will be discussed in this section 1.7.

  • Atomic Mass

  • Average Atomic Mass

  • Molecular Mass

  • Formula Mass

1.8 Mole Concept and Molar Masses: Mole and molar mass are basic terms in chemistry that describe quantities and masses of substances in a systematic manner. These terms are important for understanding and performing calculations in chemical reactions.

1.9 Percentage Composition: In chemistry, percentage composition is a measure of the relative weight of each element in a compound, expressed as a percentage of its mass.
in this section, following subtopics will be discussed:

  • Empirical formula for molecular formula

1.10 Stoichiometry and Stoichiometric Calculations: The concept of stoichiometry is fundamental to the study of chemical reactions. It is concerned with the relationship between reactants (reagents) and products (products) in a reaction. The balanced chemical equation is used to predict the quantities of reactants and reactants consumed in a reaction, as well as the quantities of products formed during the reaction. The molar ratios of reactants in a reaction are determined by stoichiometric calculations.

In this section, following subtopics will be discussed:

  • Limiting Reagent

  • Reactions in solutions

Key Points of Class 11 Chemistry NCERT Solutions Chapter 1

  • There are three types of matter in the universe which are solid, liquid, and gas.In these states, the constituents of matter are held in various ways and exhibit their specific properties. Matter can also be categorized as an element, a compound or a mixture. An element has only one type of particle, which can be an atom or a molecule. A compound is formed when two or more atoms of one or more elements come together in a uniform ratio. Mixtures are common and most of the substances in our environment are mixtures.

  • When it comes to measuring a substance’s properties, measurement is a natural part of the process. Quantification of properties necessitates a measurement system and units in which quantities are to be measured. There are many systems of measurement, of which English and Metric Systems are the most widely used. However, the scientific community has agreed on a single and universal system of measurement, commonly referred to as SI units, or International System of Units.

  • Dalton's atomic theory states that atoms are the building blocks of matter, and that the combination of various atoms is governed by fundamental laws of chemical combination. These laws include the laws of conservation of mass, law of finite proportion, law of multiple proportion, law of reciprocal proportion and Gay Lussac's law of gas volumes, as well as Avogadro's law. All of these laws ultimately led to Dalton's atomic theory.

  • Stoichiometry is a quantitative study of chemical reactions, which are chemical reactions in which various elements and compounds undergo chemical changes. The coefficients of the reaction measure the molar ratio and the number of particles involved in a reaction. Stoichiometric calculations are used to determine the number of reactants or products needed to produce a given amount of product, and vice versa.

Benefits of Downloading the PDF of NCERT Solutions Class 11 Chemistry Chapter 1 Some Basic Concepts of Chemistry

There are several benefits of downloading the pdf of NCERT solutions class 11 chemistry chapter 1 some basic concepts of chemistry. Some of the advantage are following:

Comprehensive coverage: The NCERT solutions are comprehensive and cover all the relevant topics and concepts mentioned in this chapter. 

Accuracy: The solutions are prepared by the subject matter experts to ensure accuracy and relevance of the content.The solutions provide step by step explanation for each question. The clarity of the answers makes it easier for the students to comprehend the basic concepts. 

Practice and Revision: Students can build a solid foundation in chemistry with the help of NCERT solutions. With the PDF format, students can practice and revise extensively with a wide range of questions. The regular practice and revision is essential for the students to better retain and understand the subject matter. 

Understanding concepts: The solutions explain concepts clearly and concisely, which helps students to overcome their doubts and misunderstandings. This gives them a better understanding of fundamental chemistry concepts.

Time management: Students can save time by using the NCERT Solutions which are created by eSaral. They can refer to the solutions easily to understand complex problems. This helps them to manage study time more effectively.

Proficiency: By understanding the solutions and practicing the questions from the PDF, students can perform better in exams and improve their grades.

Frequently asked questions:

Question 1: What is the law of conservation of mass ?

Answer 1 : Lavoisier’s Law of Conservation of Mass was first proposed in 1789. Lavoisier conducted extensive experiments on combustion reactions and concluded that there is no ‘net change’ in mass during all physical and chemical changes. Therefore, Lavoisier concluded that matter cannot be created or destroyed.

Question 2:  What is law of multiple proportions ?

Answer 2 : Dalton's law, first proposed in 1803, states that if two elements are able to combine to form a compound, the ratio of the mass of one element to the mass of the remaining element is in the form of a small whole number.