NCERT Solutions for Class 11 Chemistry

NCERT Solutions for Class 11 Chemistry from Goprep are helpful in enabling students to develop a strong base for all important chapters in Class 11th Chemistry. The solutions are prepared by subject experts to give simple, concise and accurate study material to students. Our NCERT Class 11 Chemistry Book Solutions provide a detailed explanation of important concepts such as Chemical Bonding, Atom, Periodicity, Equilibrium, s-Block & p-Block Elements, and others.

Scoring good marks in Chemistry is important if you want to make a good career in Engineering, Healthcare or Biochemistry. You need to strengthen your foundation and question-solving skills which can only be done by understanding complex Chemistry concepts in detail. So, if you are facing trouble solving difficult Chemistry Textbook problems you can simply refer to our NCERT Solutions for Class 11th Chemistry.

NCERT Class 11 Chemistry Solutions - All Chapters

NCERT Solutions for Class 11 Chemistry (Chapter-wise Description)

Chapter 1: Some Basic Concepts of Chemistry

Introduction: Chemistry is the branch of science that deals with the study of various properties of chemical substances and their reactions with compatible elements. Chemistry has a wide range of applications in various fields such as agriculture, food and technology, health sector etc. 

From your previous knowledge of NCERT Chemistry textbooks, you can recall that matter is made up of tiny particles, which as a whole has a mass and occupy space. In Class 11 Chemistry textbook, you will re-explore various familiar topics such as classification of matter based on its physical and chemical properties, elements/compounds, mixtures, etc. 

Further, you have to grasp the fundamental units of basic physical quantities. Most importantly, you will learn to recognize various equipment and devices used in the Chemistry lab for doing experiments. Know the complete list of topics of NCERT Class 11 Chemistry chapter-1 below. 

Topics

• Importance of Chemistry
• Matter and its Classification
• Properties of Matter and their Measurements
• Some commonly used Equipments and Devices
• Units of Measurement
• Scientific Notation
• Significant Figures
• Dimensional Analysis
• Laws of Chemical Combinations
• Dalton’s Atomic theory
• Mole Concept
• Stoichiometry and Stoichiometric Calculations
• Limiting Reactant/ Reagent
• Reactions in Solutions

Important Formulas of “Some Basic Concepts of Chemistry”

1. Relation between Kelvin Scale and Celsius Scale

K = °C + 273.15

2. Relation between Fahrenheit and Celsius Scale

°F = (9/5) °C + 32

3. Density = Mass/ Volume

4. Mass % of an element = (Mass of that element in the compound/ Molar mass of the compound) x 100

5. Reactions in solutions

(a). Mass % = (Mass of solute/ Mass of solution) x 100

(b). Mole Fraction 

 (i). Mole Fraction of solute in the solutions (x₂) = n₂/ (n₁ + n₂)

 (ii). Mole Fraction of solvent in the solutions (x₁) = n₁/ (n₁ + n₂)

(c). Molarity (M) = Number of moles of solute/ Volume of solution in litres

(d). Molality (m) = Number of Moles of Solute/ Mass of the solvent in kg)

Chapter 2: Structure of Atom

Introduction: We know that atoms as the smallest parts of an element, which consists of a nucleus, circular orbits, and three fundamental particles- electrons, protons, and neutrons. According to Rutherford, the structure of an atom resembles the solar system, where the nucleus is found at the centre while the electrons revolve around it in circular orbits. 

Rutherford’s model was a drastic improvement over Thomson’s model. In J.J Thomson’s atomic model, the atom was thought to be a composition of positively charged electricity with electrons embedded in it. Later in this chapter, you will find out that it was Neil Bohr who introduced the first atom of the periodic table- Hydrogen. 

From the exam point of view, you have to study the following topics from the NCERT Class 11 Chemistry textbook. In total, there are 69 questions in chapter-2 “Structure of Atom”. 

Topics

• Discovery of Electron- Discharge Tube Experiment
• Discovery of Proton- Anode Rays
• Thomson Model of Atom
• Rutherford’s ɑ-particle Scattering Experiment
• Rutherford’s Nuclear Model of an Atom
• Atomic Number and Mass Number 
• Isotopes and Isobars
• Bohr’s Model of Atom
• Electromagnetic Wave Theory
• Black Body Radiation
• Planck’s Quantum Theory
• Photoelectric Theory
• Dual Behaviour of Electromagnetic Radiation
• Spectrum
• Line Spectrum of Hydrogen
• Dual Behaviour of Matter
• Heisenberg’s Uncertainty Principle
• Quantum Mechanical Model of Atom
• Quantum Numbers
• Shapes of s-, p- and d-orbitals
• Aufbau Principle
• Electronic Configuration of Atoms
   

Important Formulas/ Values of “Structure of Atom”

1. Charge of an electron (e) = - 1.6022 x 10^-19 C 

2. Mass of electron (m_e) = 9.1094 x 10^-31 kg
 

3. 1 Amstrong = 10^-10 m
 

4. Wavenumber = 1/ƛ
 

5. Planck’s Quantum Theory 

    E = hv, where h is a proportionality constant

6. E= hv = W₀ + ½ mv² 

7. Dual Behaviour of Matter (de Broglie Equation)

    ƛ = h/ mv = h/P, where m = mass of the particle, 

                                       v = velocity of particle, 

                                       P= momentum of the particle

Chapter 3: Classification of Elements and Periodicity in Properties

Introduction: Till now, scientists have successfully discovered 118 elements, which have been arranged in the periodic table in increasing order according to the number of protons in their nuclei. These atoms are arranged in 7 horizontal rows (periods) and 18 vertical columns (groups or families). Across the periods, elements have been arranged in increasing order of their electrons. 

Based on the electronic configuration, there are 4 types of elements in the periodic table. These are s-block, p-block, d-block, and f-block elements. More than 78% of the elements of the periodic table are metals, and the remaining elements are non-metals. 

Further, in this chapter, you will observe periodic trends such as atomic sizes, electron gain enthalpies, electronegativity, ionization enthalpies, and valence. There are 40 questions in this chapter from the following topics.

Topics 

• Genesis of Periodic Classification Dobereiner’s Triads
• Newlands’ Law of Octaves
• Mendeleev’s Periodic Table
• Modern Periodic Law
• Structural Features of the Periodic Table
• Metals, Non-Metals, and Metalloids
• Noble Gases
• Representative, Transition, and Inner Transition Elements
• Periodic Trends in Properties of Elements
• Variation of Atomic Radius in the Periodic Table
• Ionic Radius
• Ionization Enthalpy
• Variation of Ionization Enthalpies in the Periodic Table
• Electron Gain Enthalpy
• Factors affecting Electron Gain Enthalpy
• Electronegativity
• Periodic Trends in Chemical Properties along a Period
• Variation from Top to Bottom
• Anomalous Properties of Second Period Elements 

Chapter 4: Chemical Bonding and Molecular Structure

Introduction: In the NCERT Class 10 Science textbook, you were given brief information about the concept of covalent bonding and electrovalency. According to Lewis Theory of Bonding, atoms share their electron pairs so as to form an octet. In class 11, you will re-explore the topics mentioned above in detail. 

Further, you will study about crystal lattice, which can be thought of as an aggregation of positive and negative ions in an ordered arrangement. You will also develop an understanding regarding lone-pairs and bonded pairs in case of multiple bonds. 

The back-exercise of NCERT Class 11 Chemistry chapter-4 consists of 40 questions based on the following topics.

Topics

• Chemical Bond
• Octet Rule
• Valence Electrons
• Modes of Chemical Combination
• Ionic or Electrovalent Bond
• Factors Affecting the Formation of Ionic Bond
• General Characteristics of Ionic Compounds
• Covalent Bond- Lewis-Langmuir Concept
• Lewis Representation of Simple Molecules
• Important Parameters Associated with Chemical Bonds
• Resonance
• VSEPR Model
• Valence Bond Approach
• Hybridisation of Atomic Orbitals
• Molecular Orbital Theory
• Hydrogen Bond 

Important Formulas of “Chemical Bonding and Molecular Structure”

1. How to calculate formal charge on an atom in a Lewis structure?

F.C. = (Total number of valence electrons in the free atom) - (Total number of non-bonding electrons) - ½ (Total number of bonding electrons)

2. How to calculate the dipole moment?

Dipole Moment (𝝁) = Charge (Q) x Distance of Separation (d)

3. How to find a bond order?

Bond Order (B.O.) = ½ (N_b - N_a)

Chapter 5: States of Matter

Introduction: States of matter can be classified based on intermolecular forces between their constituent particles, kinetic energy of particles, and intermolecular spaces between them. Also, the amount of thermal energy used for overcoming the intermolecular interactions determines the state of matter. 

As you proceed further, you will come across “Bulk” properties of matter such as characteristics of solids and liquids, the behaviour of gases, and type of interaction between constituent particles. You will also learn a few important laws, including Avogadro law, Boyle’s law, Charles’ law, and Dalton’s law of partial pressure. 

There are 23 questions present at the end of this chapter for testing your knowledge. Check out the list of contents below. 

Topics 

• Intermolecular Forces
• Ion-induced Dipolar Interactions
• London Forces or Dispersion Forces
• Boyle’s Law
• Charles’ Law
• Gay Lussac’s Law
• Avogadro Law
• Dalton’s Law of Partial Pressure
• Kinetic Molecular Theory of Gases
• Deviation from Ideal Gas Behaviour
• Van der Waals Equation
• Liquefaction of Gases
• Surface Tension
• Viscosity

Important Formulas of “States of Matter”

1. Boyle’s Law (Pressure-Volume Relationship)

PV = K, where V is the volume

                      P is the pressure

                      K is a constant of proportionality

2. Charles' Law (Volume-Temperature Relationship)

V/ T = constant

3. Gay Lussac’s Law (Pressure-Temperature Relationship)

P/T = constant

4. Ideal Gas Equation

PV = nRT, where R is called Universal Gas Constant

5. Compressibility Factor (Z)

Z = PV/ nRT

For ideal gas Z = 1

For real gas Z ≠ 1<

6. Van der Waals Equation

For one mole of a gas (P + a/V²) (V - b) = RT

Chapter 6: Thermodynamics

Introduction: In the sixth chapter of the NCERT Class 11 Chemistry textbook, you will be introduced to the concept of “Thermodynamics”. You will find out how thermal energy can be converted into other forms of energy and how it affects matter. For a better understanding of this concept, we can divide the universe into the system and the surroundings. 

According to the first law of Thermodynamics, change in internal energy depends on the initial and final states only and is called a state function. Later, you will learn state functions, including enthalpy and entropy.

Based on your understanding of the following topics, you will find 22 questions after the chapter ends. 

Topics 

• Important Terminologies (Open System, Isolated System, Isothermal Process, Adiabatic Process, and more)
• Internal Energy
• Enthalpy
• Intensive and Extensive Properties
• Heat Capacity
• Molar Heat Capacity
• Enthalpy Changes During Phase Transformation
• Standard Enthalpy of Formation
• Thermochemical Equation
• Hess’s Law of Constant Heat Summation
• Born-Haber Cycle
• Spontaneity
• Entropy
• Gibbs Energy and Spontaneity

Important Formulas of “Thermodynamics”

1. How to calculate enthalpy?

H = U + PV 

2. How to calculate the change in entropy?

ΔS = S_{final state} - S_{initial state}

3. Equation of Gibbs Energy

ΔG = ΔH - TΔS

Chapter 7: Equilibrium

Introduction: In this chapter, you will study how equilibrium can be established for both physical and chemical processes. In general, when the rate of the forward reaction equals the reverse reaction, then this process is termed as “Equilibrium”. 

Later in the chapter, you will learn to predict the direction of reaction by finding out reaction quotient Q, which is equal to Kc at equilibrium. Using Le Chatlier’s principle, you can study the effect of various factors such as catalyst, concentration, inert gases, pressure, and temperature on the direction of equilibrium. 

In total, there are a total of 73 questions from this chapter. These questions are based on the following topics.

Topics 

• Chemical Equilibrium
• Equilibrium in Physical Processes
• Equilibrium involving Dissolution of Solid in Liquid
• Equilibrium between a Gas and its Solution in Liquid
• Henry’s Law
• Equilibrium in Chemical Processes
• Equilibrium in Homogeneous System
• Law of Chemical Equilibrium
• Factors affecting Equilibrium
• Ionic Equilibrium in Solution
• Arrhenius Concept of Acids and Bases
• Bronsted-Lowry Acids and Bases
• Acid and Base as Conjugate Pairs
• Lewis Acids and Bases
• Common Ion Effect
• Buffer Solutions
• Solubility Products
• Equilibrium
• Equilibrium Constant
• Le Chatelier's Principle

Important Formulas of “Equilibrium”

1. Law of Chemical Equilibrium

K_c = [C]^c [D]^d/ [A]^a [B]^b or K = e^-ΔG/RT

Chapter 8: Redox Reactions

Introduction: Redox reactions are the class of reactions in which oxidation and reduction take place at the same time. In the case of oxidation, oxygen/ electronegative elements are added to a substance or hydrogen/electropositive elements are removed from a substance. On the other hand, reduction refers to the removal of oxygen/ electronegative element from a substance or addition of hydrogen/ electropositive element to a substance.

Topics 

• Oxidation
• Reduction
• Redox Reaction in Terms of Electron Transfer Reaction
• Competitive Electron Transfer Reactions
• Oxidation Number
• Rules for Assigning Oxidation Numbers
• Fractional Oxidation Numbers
• Balancing of Redox Reactions
• Redox Reactions as the Basis for Titration
• Limitation of Concept of Oxidation Number
• Redox Reactions and Electrode Processes

Important Equations of “Redox Reactions”

1. Examples of Oxidation

2Mg(s) + O₂(g) → 2Mg0 (s)

2H₂S (g) + O₂ (g) → 2S (s) + 2H₂O (l)

2. Examples of Reduction

2HgO(s) → 2Hg (l) + O₂ (g) (Removal of oxygen from mercuric oxide with the application of heat)

2FeCl₃ (aq) + H₂ (g) → 2FeCl₂ (aq) + 2HCl (aq)(Removal of electronegative element, chlorine from ferric chloride)

Chapter 9: Hydrogen

Introduction: You have already studied the Hydrogen atom model by Neil Bohr in chapter-2. Now, you will examine the resemblance of hydrogen with alkali metals, halogens (fluorine, chlorine, bromine and iodine). Further, you will learn about occurrence of hydrogen, isotopes of hydrogen (protium, deuterium, tritium), preparation of dihydrogen, properties of dihydrogen etc. 

Check out the complete list of topics of chapter 9 below.

Topics 

• Electronic Configuration of Hydrogen
• Resemblance of Hydrogen with Alkali Metals
• Resemblance of Hydrogen with Halogens
• Occurence of Hydrogen
• Isotopes of Hydrogen
• Preparation of Dihydrogen (H2)
• Hydrides
• Metallic/ Non-Stoichiometric Hydrides
• Water and its Structure
• Hydrates Formation
• Hard and Soft Water
• Heavy Water
• Hydrogen as a Fuel

Important Equations of “Hydrogen”

1. Preparation of Dihydrogen (H₂)

Zn + 2NaOH → Na₂ZnO₂ + H₂

2. Heavy Water (D₂O)

CaC₂ + 2D₂O → C₂D₂ + Ca(OD)₂

SO₃ + D₂0 → D₂SO₄

Al₄C₃ + 12D₂O → 3CD₄ + 4Al (OD)₃

Chapter 10: The s-Block Elements

Introduction: The s-Block elements of the periodic table comprises Group 1 (alkali metals) and Group 2 (alkaline earth metals). In the case of alkali metals, there is one s-electron while the alkaline earth metals are characterised by the presence of two electrons in the valence shell of their atoms. 

In this chapter, you will notice a regular trend in the physical and chemical properties of the alkali metal. With an increase in atomic number, atomic and ionic size increases whereas ionization enthalpies decrease systematically down the group. In the latter half of the chapter, you will learn how sodium hydroxide is manufactured by the Castner-Kellner process and also the formation of sodium carbonate by the Solvay process. 

There are 39 questions in this chapter, which would require you to have knowledge regarding the topics given below.

Topics 

• General Electronic Configuration of s-Block Elements
• Group 1 Elements: Alkali Metals
• Atomic and Ionic Radii
• Ionization Enthalpy
• Hydration Enthalpy
• Physical Properties
• Chemical Properties of Alkali Metals
• Uses of Alkali Metals
• Group 2 Elements: Alkaline Earth Metals
• Electronic Configuration
• Ionization Enthalpies
• Hydration Enthalpies
• General Characteristics of Compounds of Alkaline Earth metals 

Chapter 11: The p-Block Elements

Introduction: After studying this chapter, you will be able to understand the general trends in the Chemistry of p-Block elements. Also, you will develop a thorough understanding of trends in physical and chemical properties of group 13 and group 14 elements. Further, you will understand the anomalous behaviour of boron and carbon. 

Nearing conclusion, you will learn to describe allotropic forms of carbon, know the chemistry of some important compounds of boron, carbon and silicon. Finally, you can prepare a list of important uses of group 13 and 14 elements. 

NCERT Class 11 Chemistry Solutions will provide you with self-explanatory answers to a total of 44 questions present at the end of the chapter. Check out the complete list of topics below.

Topics 

• p-Block Elements
• Group 13 Elements: The Boron Family
• Some Compounds of Boron
• Group 14 Elements
• Anomalous Behaviour of Carbon
• Allotropes of Carbon
• Some Important Compounds of Carbon and Silicon

Important Equations of “The p-Block Elements”

1. Industrial method of preparation of Diborane (B₂H₆)

2BF₃ + 6NaH → B₂H₆ + 6NaF

2. Preparation of Carbon Monoxide (CO)

2C (s) + O₂ (g) → 2CO (g)

HCOOH (at 373K) with catalyst Con. H₂SO₄ → H₂0 + CO (For small scale preparation)

3. Preparation of Carbon Dioxide 

C (s) + O₂ (g) (with application of heat) → CO₂ (g)

CH₄ (g) + 2O₂ (g) (with application of heat) → CO₂ (g) + 2H₂O (g)

Chapter 12: Organic Chemistry- Some Basic Principles and Techniques

Introduction: Organic Chemistry in one of the three branches of Chemistry that you will come across in NCERT Class 12 Chemistry textbook. However, in class 11, you will read a brief introduction and learn to classify the organic compounds. Besides, you will also learn to form structures of organic compounds. 

The next big thing that you will come across is the IUPAC system of nomenclature. In the latter half of the chapter, you will understand the concept of an organic reaction mechanism. Finally, you will learn the basic principles involved in the quantitative analysis of organic compounds.  

Topics 

• Organic Chemistry
• Homologous Series
• Nomenclature of Organic Compounds
• IUPAC System
• Isomerism
• Fundamental Concepts in Organic Reaction Mechanism
• Orbital Concept of Hyperconjugation
• Qualitative Analysis of Organic Compounds
• Quantitative Analysis

Important Equations of “ Organic Chemistry- Some Basic Principles and Techniques”

1. Detection of Carbon and Hydrogen

C + 2CuO → CO₂ + 2Cu

2H + CuO → H₂O + Cu

CO₂ + Ca(OH)₂ → CaCO₃ ↓ + H₂O

2. Lassaigne’s test (Detection of Nitrogen, Sulphur, Halogens, and Phosphorus)

Na + C + N → NaCN

2Na + S → Na₂S 

Na + X → NaX

3. Test for Nitrogen

Na + C + N → NaCN (The substance is heated with sodium metal)

FeSO₄ + 2NaOH → Fe(OH)₂ + Na₂SO₄ (Ferrous sulphate solution is boiled with the waster extract of the fused mass)

6NaCN + Fe(OH)₂ → Na₄[Fe(CN)₆] + 2NaOH (Sodium ferrocyanide is obtained)

3Na₄ [Fe(CN)₆] + 4FeCl₃ → Fe₄[Fe(CN)₆]₃ + 12NaCl (Prussian Blue solution is obtained)

4. Sodium Test

Na + S → Na₂S (Sodium Sulphide is obtained upon the fusion of sodium with sulphur)

Pb (CH₃COO)₂ + Na₂S → PbS + 2CH₃COONa (Lead Sulphide is obtained)

5. Test for Halogens (Sodium Test)

Cl + Na → NaCl

Br + Na → NaBr

I + Na → Nal

6. Test for Phosphorus

Na₃PO₄ + 3HNO₃ → H₃PO₄ + 3NaNO₃ (Sodium peroxide is boiled with HNO₃ 

H₃PO₄ + 12(NH₄)2MoO₄ + 21HNO₃ → 12H₂O + 21NH₄NO₃ + (NH₄)3PO₄. 12MoO₃ (H₃PO₄ is now reacted with Ammonium Molybdate)

Chapter 13: Hydrocarbons

Introduction: Chapter 13 of NCERT Class 11 Chemistry is about hydrocarbons, which are compounds made of carbon and hydrogen. Based on the number of bonds, a hydrocarbon can be classified into saturated (single-bond) and unsaturated hydrocarbon (double or triple bond). IUPAC nomenclature is done depending upon the number of carbon atoms in a compound. 

Later on, you will explore various methods of preparation of hydrocarbons. You will also learn to distinguish between various conformations of ethane. As the chapter is lengthy, there are 41 questions in the back exercise. 

Topics 

• Hydrocarbons
• Classification of Hydrocarbons
• Alkanes
• Nomenclature Guidelines
• Newman Projections
• Relative Stability of Conformations
• Alkenes
• Isomerism
• Alkynes

Chapter 14: Environmental Chemistry

Introduction: Environmental Chemistry deals with the study of chemical substances occurring in the environment. In this chapter, we will also discuss major topics related to environmental threats, which are actively debated these days. These include acid rain, atmospheric pollution, global warming, and the greenhouse effect. 

Ozone layer depletion, water pollution, and soil pollution are other major causes for our planet’s devastation. We will discuss all these topics in detail and learn strategies to overcome them. 

Topics

• Environmental Chemistry
• Environmental Pollution
• Pollutants
• Troposphere
• Stratosphere
• Oxides of Sulphur
• Oxides of Nitrogen
• Oxides of Carbon
• Global Warming and the Greenhouse Effect
• Particulate Pollutants
• Smog
• Stratospheric Pollution
• Water Pollution
• BOD (Biochemical Oxygen Demand)
• Chemical Pollutants
• International Standards for Drinking Water
• Soil Pollution and its Sources
• Green Chemistry

Benefits of NCERT Class 11 Chemistry Solutions

• Explained in a step-by-step format to provide in-depth knowledge of concepts
• Reliable solutions prepared by experts for organic and inorganic Chemistry
• Difficult questions are explained easily through illustrations and examples
• The best resource for preparing for the 11th Class Chemistry exam and competitive exams
• Help students score better marks in the exam
• Solutions are easily available and can be accessed free of cost.

Final Words

If you want to gain a competitive edge over your Class 11th Chemistry preparations, then it is important that you make use of best study material. With NCERT Class 11 Chemistry Solutions, you can definitely make your preparation in the right direction. These solutions foster quick learning and understanding of complex Chemistry concepts which can help you score better in the exam.