Table of Contents
If you are a student in Class 11 studying Chemistry, you may have come across the NCERT Solutions. This textbook is an important resource for understanding the basics of chemistry and its applications. Chapter 1 of the NCERT Chemistry Solutions introduces students to some fundamental concepts of chemistry. In this chapter, students learn about important topics such as the nature of matter, the laws of chemical combination, and the concept of moles.
Understanding these basic concepts is crucial for building a strong foundation in chemistry, as they help explain how substances interact and change during chemical reactions. NCERT solutions for Chapter 1 provide clear explanations and step-by-step answers to the questions in the textbook, making it easier for students to grasp the material. These solutions are designed to help students practice and reinforce their learning, ensuring they are well-prepared for exams and future studies in chemistry.
Whether you are studying chemistry class 11 chapter 1 or looking for NCERT Solutions for Class 11, the solutions for Chapter 1 of the Class 11 Chemistry NCERT textbook are a valuable resource. They cover all the important topics in a clear and concise manner, making it easier for students to understand and apply the concepts. Chemistry chapter 1 class 11 NCERT solutions are particularly helpful for students who are struggling with a specific topic or just want to review their understanding of the material.
Chapter 1 class 11 chemistry NCERT solutions are available in various formats, including online and printed versions. These NCERT solutions are created by experienced teachers and subject matter experts, ensuring that the content is accurate, up-to-date, and aligned with the NCERT curriculum. Whether you prefer to study online or prefer printed material, there are NCERT Solutions for Class 11 Chemistry ch 1 available to suit your learning style and preferences.
NCERT Solutions for Class 11 Chemistry Chapter 1 PDF Download
Get ready to ace your studies with the NCERT Solutions for Class 11 Chemistry Chapter 1! This PDF download provides clear answers and explanations for all the questions in the chapter. It’s a helpful resource for students to understand key concepts and prepare effectively for exams. Download your copy today!
Class 11 Chemistry NCERT Solutions Chapter 1 Question with Answer
Ques: Define mole concept.
Ans: The mole concept is a method used to express the amount of a chemical substance. One mole of any substance contains exactly 6.022 × 1023 entities (atoms, molecules, ions, etc.). This number is known as Avogadro’s number.
Explanation: The mole concept allows chemists to count particles by weighing them. Since atoms and molecules are extremely small, a convenient quantity like the mole helps in dealing with macroscopic amounts of material. For example, one mole of carbon-12 atoms weighs exactly 12 grams and contains 6.022 × 1023 atoms.
Ques: Calculate the number of moles in 90 grams of water (H2O).
Ans: The molar mass of water (H2O) is 18 g/mol. Number of moles = Mass / Molar mass = 90 g / 18 g/mol = 5 moles.
Explanation: To calculate the number of moles, we use the formula: Number of moles = Given mass / Molar mass. For water, the molar mass is calculated as: 2 × 1 + 16 = 18 g/mol. Thus, 90 grams of water is equal to 5 moles.
Ques: What is empirical formula? How is it different from molecular formula?
Ans: The empirical formula of a compound is the simplest whole number ratio of the atoms of each element in the compound. The molecular formula shows the actual number of atoms of each element in a molecule of the compound.
Explanation: For example, the empirical formula of glucose is CH2O, which shows the simplest ratio of carbon, hydrogen, and oxygen atoms. However, the molecular formula of glucose is C6H12O6, indicating that a molecule of glucose contains 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms.
Ques: Define molarity and calculate the molarity of a solution containing 5 grams of NaOH in 450 mL of solution.
Ans: Molarity (M) is defined as the number of moles of solute dissolved in one liter of solution. It is given by: Molarity (M) = Number of moles of solute / Volume of solution in liters.
First, calculate the number of moles of NaOH: Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol. Number of moles of NaOH = 5 g / 40 g/mol = 0.125 moles. Volume of solution = 450 mL = 0.450 L. Molarity = 0.125 moles / 0.450 L = 0.278 M.
Explanation: Molarity is a concentration term that expresses the moles of solute per liter of solution. The calculation involves converting the mass of the solute to moles and the volume of the solution to liters, and then dividing the moles by the liters to get molarity.
Ques: Explain the law of conservation of mass with an example.
Ans: The law of conservation of mass states that mass can neither be created nor destroyed in a chemical reaction. The total mass of the reactants is equal to the total mass of the products.
Example: In the reaction between hydrogen and oxygen to form water: 2H2 + O2 → 2H2O.
Mass of reactants: 2 × 2 + 2 × 16 = 4 + 32 = 36 g. Mass of products: 2 × 18 = 36 g.
Explanation: This example shows that the mass of hydrogen and oxygen before the reaction is equal to the mass of water formed after the reaction, demonstrating the law of conservation of mass.
Ques: Differentiate between precision and accuracy with suitable examples.
Ans: Precision refers to the closeness of two or more measurements to each other. Accuracy refers to how close a measurement is to the true or accepted value.
- Example of Precision: If a student weighs a sample three times and gets 1.21 g, 1.22 g, and 1.21 g, the measurements are precise because they are very close to each other.
- Example of Accuracy: If the true mass of a sample is 1.20 g and the student measures it as 1.19 g, the measurement is accurate because it is close to the true value.
Explanation: Precision is about consistency in measurements, while accuracy is about correctness. Both are important in scientific experiments for reliable results.
Ques: Calculate the empirical formula of a compound that contains 40% carbon, 6.7% hydrogen, and 53.3% oxygen by mass.
Ans: First, convert the percentages to grams assuming a 100 g sample: Carbon: 40 g, Hydrogen: 6.7 g, Oxygen: 53.3 g.
Next, convert grams to moles: Moles of carbon = 40/12 = 3.33, Moles of hydrogen = 6.7/1 = 6.7, Moles of oxygen = 53.3/16 = 3.33.
Now, divide by the smallest number of moles: Carbon: 3.33/3.33 = 1, Hydrogen: 6.7/3.33 = 2, Oxygen: 3.33/3.33 = 1.
Empirical formula = CH2O.
Explanation: The empirical formula is the simplest ratio of elements in a compound. By converting mass percentages to moles and then simplifying the ratio, we determine the empirical formula.
Ques: What is Avogadro’s law? How does it help in understanding the concept of molar volume?
Ans: Avogadro’s law states that equal volumes of all gases, at the same temperature and pressure, contain an equal number of molecules.
Explanation: Avogadro’s law implies that one mole of any gas occupies the same volume (22.4 L at STP). This concept of molar volume helps in comparing amounts of gases and simplifies calculations involving gases in chemical reactions.
Ques: Explain the difference between empirical formula and molecular formula with an example.
Ans: The empirical formula shows the simplest whole number ratio of atoms in a compound, while the molecular formula shows the actual number of atoms of each element in a molecule.
Example: The empirical formula of glucose is CH2O, and its molecular formula is C6H12O6.
Explanation: The molecular formula is a multiple of the empirical formula. In the case of glucose, the molecular formula indicates there are 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms in a molecule, which is a multiple of the empirical formula CH2O.
Ques: A solution is prepared by dissolving 10 grams of NaCl in 500 mL of water. Calculate the molarity of the solution.
Ans: Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol.
Number of moles of NaCl = 10 g / 58.5 g/mol = 0.171 moles.
Volume of solution = 500 mL = 0.500 L.
Molarity = 0.171 moles / 0.500 L = 0.342 M.
Explanation: Molarity is calculated by dividing the number of moles of solute by the volume of the solution in liters. Here, we first convert the mass of NaCl to moles and then divide by the volume of the solution.
NCERT Solutions for Class 11 Chemistry Ch 1 Some Basic Concepts of Chemistry
Some Basic Concepts of Chemistry is the first chapter in the Class 11 Chemistry syllabus according to NCERT for the first term. This chapter covers important topics, including the significance of chemistry, atomic mass, and molecular mass. It also discusses key laws and theories in chemistry, such as Dalton’s atomic theory, Avogadro’s law, and the law of conservation of mass.The types of questions in this chapter include:
- Numerical problems that involve calculating the molecular weight of different compounds.
- Questions that require calculations of mass percent and concentration.
- Problems related to empirical and molecular formulas.
- Questions on molarity and morality.
- Additional problems related to the mole concept, such as percentage composition and expressing concentration in parts per million.
The NCERT Solutions for Chemistry provided on this page for Class 11 Chapter 1 offer clear explanations and steps to follow when solving numerical questions, which are commonly asked in first-term exams. Below are the subtopics covered in this chapter.
Subtopics of NCERT Solutions for class 11 Chapter 1
- Importance Of Chemistry
- Nature Of Matter
- Properties Of Matter And Their Measurement
- The International System Of Units (Si)
- Mass And Weight
- Uncertainty in Measurement
- Scientific Notation
- Significant Figures
- Dimensional Analysis
- Laws Of Chemical Combinations
- Law Of Conservation Of Mass
- Law Of Definite Proportions
- Law Of Multiple Proportions
- Gay Lussac’s Law Of Gaseous Volumes
- Avogadro Law
- Dalton’s Atomic Theory
- Atomic And Molecular Masses
- Atomic Mass
- Average Atomic Mass
- Molecular Mass
- Formula Mass
- Mole Concept And Molar Masses
- Percentage Composition
- Empirical Formula For Molecular Formula
- Stoichiometry And Stoichiometric Calculations
- Limiting Reagent
- Reactions In Solutions
About Infinity Learn Solutions
Infinity Learn aims to provide top-quality learning materials for students. Our goal is to improve students’ learning abilities. The solutions we offer are carefully designed to provide many benefits for those who use our study materials. That’s why they are created by experts who focus on explaining concepts clearly.
If students need help with the NCERT Solutions for Class 11, they can reach out to our support team, who are ready to answer any questions. For a better learning experience, students can also visit the Infinity Learn website.
Class 11 Chemistry Chapter 1 Some Basic Concepts of Chemistry FAQs
What topics are covered in Chapter 1 of NCERT Class 11 Chemistry?
Chapter 1, Some Basic Concepts of Chemistry, covers essential topics such as the mole concept, molar mass, stoichiometry, and the principles of chemical calculations. It also introduces students to the concept of the law of conservation of mass and the significance of chemical formulas.
How can NCERT Solutions help in understanding this chapter?
NCERT Solutions provide detailed explanations and step-by-step solutions to the exercises and problems in Chapter 1. They help students grasp the fundamental concepts, practice problem-solving, and prepare effectively for exams by clarifying doubts and reinforcing learning.
Are NCERT Solutions for Class 11 Chemistry Chapter 1 available for free?
Yes, NCERT Solutions for Class 11 Chemistry Chapter 1 are available for free on various educational Infinity Learn websites and platforms. Students can easily access these resources to enhance their understanding of the chapter.
What is the importance of the mole concept in chemistry?
The mole concept is crucial in chemistry because it provides a bridge between the atomic scale and the macroscopic scale. It allows chemists to count particles (atoms, molecules, ions) in a sample by using a standard unit called the mole, making it easier to perform calculations related to chemical reactions and stoichiometry.
How can I effectively study Chapter 1 of NCERT Class 11 Chemistry?
To effectively study Chapter 1, start by reading the NCERT textbook thoroughly to understand the basic concepts. Use NCERT Solutions to practice problems and clarify any doubts. Additionally, make summary notes, solve previous years' question papers, and engage in group discussions to reinforce your understanding and retention of the material.
