In chemistry, a hydrogen bond is an electrostatic force of attraction between a hydrogen atom and another electronegative atom. It is a special type of dipole-dipole force. Hydrogen bonding is the phenomenon of the formation of Hydrogen Bonds.

Hydrogen Bonding–Definition, Types, Effects and Properties

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In chemistry, a hydrogen bond is an electrostatic force of attraction between a hydrogen atom and another electronegative atom. It is a special type of dipole-dipole force. Hydrogen bonding is the phenomenon of the formation of Hydrogen Bonds.

H Bonds are stronger than any dipole-dipole bonds but weaker than covalent bonds. Hydrogen bonds can form between atoms within a molecule or between two different molecules.

Hydrogen bonds can form when:

  • A hydrogen atom is covalently bonded to a more electronegative atom
  • The other atom has a lone pair of electrons

Examples of hydrogen bonds Water, Ammonia, and Hydrogen Fluoride.

What is Hydrogen Bond?

A hydrogen bond is a type of electrostatic force of attraction between a hydrogen atom and another electronegative atom. It is a type of intermolecular force. The hydrogen atom is covalently bonded to a more electronegative “donor” atom or group, and the other atom has a lone pair of electrons. The hydrogen atom is called the H-bond donor, and the other atom is called the H-bond acceptor.

Hydrogen bonds are weak, intermolecular bonds that hold together soft matter, water, network liquids, and many ferroelectric crystals. For example, water is a liquid over a wider range of temperatures than expected for its size because of its extensive hydrogen bonding. Water is also a good solvent for ionic compounds and many others because it readily forms hydrogen bonds with the solute.

Formation of Hydrogen Bonds

Hydrogen bonds form when a hydrogen atom that is covalently bonded to an electronegative atom (such as oxygen, nitrogen, or fluorine) interacts with another electronegative atom nearby. The formation of hydrogen bonds is illustrated as follows:

  1. Polar Covalent Bond: Initially, there is a polar covalent bond between a hydrogen atom (H) and an electronegative atom (let’s say oxygen, O). In a water molecule (H2O), for example, each hydrogen atom forms a polar covalent bond with the oxygen atom.
  2. Electronegativity Difference: Oxygen is more electronegative than hydrogen. As a result, the shared electrons in the covalent bond spend more time around the oxygen nucleus, creating a partial negative charge (δ−) on the oxygen atom and a partial positive charge (δ+) on the hydrogen atom.
  3. Attraction between Opposite Charges: The partial positive charge on the hydrogen atom in one molecule is attracted to the partial negative charge on the electronegative atom of another molecule. For example, the partial positive charge on the hydrogen atom of one water molecule is attracted to the partial negative charge on the oxygen atom of another water molecule.
  4. Formation of Hydrogen Bond: This electrostatic attraction between the partially positive hydrogen atom and the partially negative atom of another molecule is known as a hydrogen bond. Although individually weaker than covalent or ionic bonds, hydrogen bonds collectively play crucial roles in various biological and chemical processes, such as the structure of DNA, the properties of water, and protein folding.

In short, hydrogen bonds form due to the attraction between the partial positive charge on a hydrogen atom and the partial negative charge on an electronegative atom of another molecule, leading to the formation of a weak electrostatic bond between the molecules.

What is Hydrogen Bonding?

Hydrogen Bonding is simply the formation of Hydrogen bonds. Hydrogen bonding is a type of chemical bonding that possess an electrostatic force of attraction between a hydrogen atom and an atom containing a lone pair of electrons in a chemical substance. The hydrogen must be attached to an electronegative atom for a hydrogen bond to form. It should be noted that the hydrogen bond is not a covalent bond however, the atoms present in it are covalent.

Hydrogen bonding is the formation of hydrogen bonds. Hydrogen bonds are the type of attractive intermolecular forces caused by the dipole-dipole interaction between a hydrogen atom bonded to a strongly electronegative atom of the same or another nearby electronegative atom. 

Hydrogen is covalently bound to the more electronegative oxygen atom in water molecules (H2O). As a result of dipole-dipole interactions between the hydrogen atom of one water molecule and the oxygen atom of another H2O molecule, hydrogen bonding occurs in water molecules.

The bond pair of electrons in the O-H bond is quite close to the oxygen nucleus in this case (due to the large difference in the electronegativities of oxygen and hydrogen). As a result, the hydrogen atom generates a partial positive charge (+) whereas the oxygen atom develops a partial negative charge (-). 

Important Conditions for Hydrogen Bonding

Hydrogen Bonding is possible in cases when the molecule contains a highly electronegative atom linked to the hydrogen atom. The hydrogen bonding in water is a vigorous bond between the nearest water molecule containing one Hydrogen atom between two oxygen atoms. Hydrogen bonding is major of two types of intramolecular and intermolecular hydrogen bonding, on the basis of the atoms involved in it. Hydrogen bonding is maximum in solid-state compounds.

  • The atom that is bonded to the hydrogen atom has a high electronegativity, making the bond suitably polar. A strongly electronegative atom connected to the hydrogen atom must be present in the molecule. The degree of polarisation of the molecule increases with increasing electronegativity.
  • The electronegative atom attached to the Hydrogen atom should be smaller in size. Greater the electrostatic attraction, the smaller the size. So, the smaller size should attract the bonding electron pair effectively.

Effects of Hydrogen Bonding on Elements

  1. Dissociation: HF dissociates in water and sends off the difluoride ion instead of the fluoride ion. In HF, this is due to hydrogen bonding. HCl, HBr, and HI molecules do not form hydrogen bonds. This explains why chemicals like KHCl2, KHBr2, and KHI2 don’t exist.
  2. Association: Because of hydrogen bonding, carboxylic acid molecules exist as dimers. Such compounds have molecular weights that are twice as large as those calculated from their simple formula.

Examples of Hydrogen Bonding

various examples of Hydrogen Bonding are,

Hydrogen Bond in Water (H2O)

An excellent example of Hydrogen Bonding is Water. A highly electronegative oxygen atom is connected to a hydrogen atom in the water molecule. The shared pair of electrons are attracted to the oxygen atoms more, and this end of the molecule becomes negative, while the hydrogen atoms become positive.

In chemistry, a hydrogen bond is an electrostatic force of attraction between a hydrogen atom and another electronegative atom. It is a special type of dipole-dipole force. Hydrogen bonding is the phenomenon of the formation of Hydrogen Bonds.

Hydrogen Bond in Water

Hydrogen Bond in Hydrogen Fluoride (HF)

A stronger-than-average hydrogen bond is created by hydrofluoric acid and is known as a symmetric hydrogen bond. Formic acid can also make this type of bond.

In chemistry, a hydrogen bond is an electrostatic force of attraction between a hydrogen atom and another electronegative atom. It is a special type of dipole-dipole force. Hydrogen bonding is the phenomenon of the formation of Hydrogen Bonds.

Hydrogen Bond in Ammonia (NH3)

Between the hydrogen in one molecule and the nitrogen in another, hydrogen bonds are formed. Since each nitrogen has a single electron pair, the bond that develops in the case of ammonia is relatively weak. Methylamine also has this form of hydrogen bonding with nitrogen.

In chemistry, a hydrogen bond is an electrostatic force of attraction between a hydrogen atom and another electronegative atom. It is a special type of dipole-dipole force. Hydrogen bonding is the phenomenon of the formation of Hydrogen Bonds.

Hydrogen Bond in Alcohol and Carboxylic Acid 

A type of chemical molecule with a -OH group is alcohol. In most cases, hydrogen bonding is easily generated if any molecule containing the hydrogen atom is immediately coupled to either oxygen or nitrogen.

Hydrogen Bond in Alcohol

In chemistry, a hydrogen bond is an electrostatic force of attraction between a hydrogen atom and another electronegative atom. It is a special type of dipole-dipole force. Hydrogen bonding is the phenomenon of the formation of Hydrogen Bonds.

Hydrogen Bond in Alcohols

Hydrogen Bond in Carboxylic Acid is shown ion the i9mage added below,

In chemistry, a hydrogen bond is an electrostatic force of attraction between a hydrogen atom and another electronegative atom. It is a special type of dipole-dipole force. Hydrogen bonding is the phenomenon of the formation of Hydrogen Bonds.

Hydrogen Bond in Carboxylic Acid

Strength of Hydrogen Bond: The hydrogen bond is a relatively weak one. Hydrogen bonds have a strength that is halfway between weak van der Waals forces and strong covalent bonds. The attraction of the shared pair of electrons, and hence the atom’s electronegativity, determines the hydrogen bond’s dissociation energy.

Properties of Hydrogen Bonding

  1. Volatility – The boiling point of compounds incorporating hydrogen bonding between distinct molecules is greater, hence they are less volatile.
  2. Solubility – Because of the hydrogen bonding that can occur between water and the alcohol molecule, lower alcohols are soluble in water.
  3. Lower density of ice than water – In the case of solid ice, hydrogen bonding causes water molecules to form a cage-like structure. In fact, each water molecule is tetrahedrally connected to four other water molecules. In the solid state, the molecules are not as tightly packed as they are in the liquid state. This case-like structure collapses as ice melts, bringing the molecules closer together. As a result, the volume of water reduces while the density increases for the same quantity of water. As a result, at 273 K, ice has a lower density than water. Ice floats because of this.
  4. Viscosity and Surface Tension – Hydrogen bonding is found in compounds that have an associated molecule. As a result, their flow becomes more complicated. They have high surface tension and higher viscosity.

Why do hydrogen-bonded compounds have high melting and boiling points?

The melting and boiling temperatures of hydrogen-bonded compounds are unusually high. The elevated melting and boiling points of hydrogen-bonded compounds are attributable to the additional energy required to break these bonds.

  • At room temperature, H2O is a liquid, whereas H2S, H2Se, and H2Te are all gases. Hydrogen bonding produces links in the water molecules, resulting in water having a higher boiling point than the other chemicals.
  • Because there is hydrogen bonding in NH3, but not in PH3, ammonia has a higher boiling point than PH3.
  • The presence of hydrogen bonding accounts for hydrogen fluoride’s particularly high boiling point among the halogen acids.
  • Because ethanol contains hydrogen bonds, it has a higher boiling point than diethyl ether.

Types of Hydrogen Bonding

There are two types of H bonds, which are labeled as follows:

Intermolecular Hydrogen Bonding  

Intermolecular hydrogen bonding occurs when hydrogen bonds are formed between molecules of the same or distinct substances. Hydrogen bonding in water, alcohol, and ammonia, for example.

In chemistry, a hydrogen bond is an electrostatic force of attraction between a hydrogen atom and another electronegative atom. It is a special type of dipole-dipole force. Hydrogen bonding is the phenomenon of the formation of Hydrogen Bonds.

Depiction of Intermolecular Hydrogen Bonding

Intramolecular Hydrogen Bonding

Intramolecular hydrogen bonding refers to hydrogen bonding that occurs within a single molecule. It occurs in compounds with two groups, one of which has a hydrogen atom linked to an electronegative atom and the other of which has a highly electronegative atom linked to a less electronegative atom of the other group. The link is created between the more electronegative atoms of one group and the hydrogen atoms of the other group.

In chemistry, a hydrogen bond is an electrostatic force of attraction between a hydrogen atom and another electronegative atom. It is a special type of dipole-dipole force. Hydrogen bonding is the phenomenon of the formation of Hydrogen Bonds.

Depiction of Intramolecular Hydrogen Bonding

Difference between a Hydrogen Bond and Covalent Bond

The distinction between hydrogen bonds and covalent bonds lies primarily in their mechanism of formation, strength, and the nature of the interaction:

  1. Formation:
    • Covalent bonds form through the sharing of electron pairs between atoms, resulting in a strong bond.
    • Hydrogen bonds form due to the attraction between a hydrogen atom bonded to an electronegative atom and another electronegative atom in a different molecule or within the same molecule.
  2. Strength:
    • Covalent bonds are relatively strong and require a substantial amount of energy to break.
    • Hydrogen bonds are weaker compared to covalent bonds but stronger than van der Waals forces, which are another type of intermolecular force.
  3. Nature of Interaction:
    • Covalent bonds involve the sharing of electrons, leading to a stable molecular structure.
    • Hydrogen bonds are dipole-dipole attractions between molecules or within the same molecule, contributing to the structure and properties of substances such as water, DNA, and proteins.

Practice Questions on Hydrogen Bonds

Q1: Describe the formation and significance of hydrogen bonds in water molecules. How do hydrogen bonds contribute to the unique properties of water?

Q2: Explain the role of hydrogen bonds in maintaining the secondary structure of proteins. Provide examples of secondary structures stabilized by hydrogen bonding.

Q3: Discuss the importance of hydrogen bonds in the stability of the DNA double helix structure. How do hydrogen bonds contribute to the pairing of nitrogenous bases in DNA?

Q4: Describe the formation of hydrogen bonds between molecules of ammonia (NH3) and water (H2O). Include the polarity of molecules and the arrangement of hydrogen bonds in your explanation.

Q5: Compare and contrast hydrogen bonds with other types of intermolecular forces, such as dipole-dipole interactions and van der Waals forces. Provide examples to illustrate the differences in strength and mechanism of each type of interaction.

FAQs on Hydrogen Bonding

State Octet Rule.

Atoms are most stable when their valence shells are filled with eight electrons, according to the octet rule. It is based on the observation that the atoms of the major group elements have a proclivity for chemical bonding in such a way that each atom in the resulting molecule has eight electrons in the valence shell. Only the core group elements are subject to the octet rule.

What are the factors that affect the formation of Ionic Bond?

Factors affecting the formation of Ionic Bond are:- 

  • Ionization Enthalpy
  • Electron Gain Enthalpy
  • Lattice Energy

List any three characteristics of Ionic Compounds.

Characteristics of Ionic Compounds are as follows:

  1. The melting and boiling points of ionic compounds are usually quite high. This is due to the strong electrostatic forces that hold ions together in ionic compounds.
  2. Ionic compounds are frequently found in solid form.
  3. Ionic compound solutions are excellent electrical conductors. In their molten condition, they are also good conductors of electricity.

What is Hydrogen Bonding?

When a hydrogen atom is coupled to a highly electronegative atom, the shared pair of electrons are attracted more by this atom, and the molecules’ negative end becomes slightly negative while the positive end becomes slightly positive.The negative end of one molecule attracts the positive end of the other, resulting in the formation of a weak bond. This connection is referred to as Hydrogen Bonding.

What are the conditions required for Hydrogen Bonding?

Conditions required for Hydrogen Bonding are:

  • A highly electronegative atom must be coupled to the hydrogen atom in the molecule. The polarisation of a molecule is proportional to its electronegativity.
  • Electronegative atom should be modest in size. The greater the electrostatic attraction, the smaller the size.

Is CH4 a hydrogen bond?

No, CH4 (methane) does not exhibit hydrogen bonding. Hydrogen bonding occurs between a hydrogen atom bonded to an electronegative atom (such as oxygen, nitrogen, or fluorine) and another electronegative atom in a different molecule or within the same molecule. In methane, hydrogen atoms are bonded to carbon, which is not electronegative enough to form hydrogen bonds.

Can HCl form hydrogen bonds?

Yes, HCl (hydrogen chloride) can participate in hydrogen bonding, but to a limited extent. Hydrogen bonding requires a hydrogen atom bonded to an electronegative atom like chlorine in HCl. However, the strength of hydrogen bonding in HCl is weaker compared to compounds like water or ammonia.

Why is ice lighter than water?

Ice is lighter than water because of its unique crystal structure. In ice, water molecules form a regular hexagonal lattice held together by hydrogen bonds, creating open spaces between the molecules. This arrangement causes ice to be less dense than liquid water, which is why ice floats on water.

Why is hydrogen bond weak?

Hydrogen bonds are relatively weak compared to covalent bonds because they involve electrostatic attractions between partially charged atoms rather than the sharing of electrons. Additionally, hydrogen bonds are weaker than covalent bonds due to their longer bond lengths and the nature of the interaction.

What is the weakest bond?

Van der Waals forces, including dispersion forces and dipole-dipole interactions, are generally considered the weakest types of chemical bonds. These forces arise from temporary fluctuations in electron distribution and are weaker than both covalent and hydrogen bonds.

What are 3 examples of a hydrogen bond?

Three examples of hydrogen bonds include:

  • Hydrogen bonds between water molecules, which contribute to the unique properties of water.
  • Hydrogen bonds between complementary nitrogenous bases in DNA, which stabilize the double helix structure.
  • Hydrogen bonds between ammonia molecules (NH3), which play a role in ammonia’s properties as a polar molecule.

Er. Neeraj K.Anand is a freelance mentor and writer who specializes in Engineering & Science subjects. Neeraj Anand received a B.Tech degree in Electronics and Communication Engineering from N.I.T Warangal & M.Tech Post Graduation from IETE, New Delhi. He has over 30 years of teaching experience and serves as the Head of Department of ANAND CLASSES. He concentrated all his energy and experiences in academics and subsequently grew up as one of the best mentors in the country for students aspiring for success in competitive examinations. In parallel, he started a Technical Publication "ANAND TECHNICAL PUBLISHERS" in 2002 and Educational Newspaper "NATIONAL EDUCATION NEWS" in 2014 at Jalandhar. Now he is a Director of leading publication "ANAND TECHNICAL PUBLISHERS", "ANAND CLASSES" and "NATIONAL EDUCATION NEWS". He has published more than hundred books in the field of Physics, Mathematics, Computers and Information Technology. Besides this he has written many books to help students prepare for IIT-JEE and AIPMT entrance exams. He is an executive member of the IEEE (Institute of Electrical & Electronics Engineers. USA) and honorary member of many Indian scientific societies such as Institution of Electronics & Telecommunication Engineers, Aeronautical Society of India, Bioinformatics Institute of India, Institution of Engineers. He has got award from American Biographical Institute Board of International Research in the year 2005.

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CBSE Class 11 Chemistry Syllabus

CBSE Class 11 Chemistry Syllabus is a vast which needs a clear understanding of the concepts and topics. Knowing CBSE Class 11 Chemistry syllabus helps students to understand the course structure of Chemistry.

Unit-wise CBSE Class 11 Syllabus for Chemistry

Below is a list of detailed information on each unit for Class 11 Students.

UNIT I – Some Basic Concepts of Chemistry

General Introduction: Importance and scope of Chemistry.

Nature of matter, laws of chemical combination, Dalton’s atomic theory: concept of elements,
atoms and molecules.

Atomic and molecular masses, mole concept and molar mass, percentage composition, empirical and molecular formula, chemical reactions, stoichiometry and calculations based on stoichiometry.

UNIT II – Structure of Atom

Discovery of Electron, Proton and Neutron, atomic number, isotopes and isobars. Thomson’s model and its limitations. Rutherford’s model and its limitations, Bohr’s model and its limitations, concept of shells and subshells, dual nature of matter and light, de Broglie’s relationship, Heisenberg uncertainty principle, concept of orbitals, quantum numbers, shapes of s, p and d orbitals, rules for filling electrons in orbitals – Aufbau principle, Pauli’s exclusion principle and Hund’s rule, electronic configuration of atoms, stability of half-filled and completely filled orbitals.

UNIT III – Classification of Elements and Periodicity in Properties

Significance of classification, brief history of the development of periodic table, modern periodic law and the present form of periodic table, periodic trends in properties of elements -atomic radii, ionic radii, inert gas radii, Ionization enthalpy, electron gain enthalpy, electronegativity, valency. Nomenclature of elements with atomic number greater than 100.

UNIT IV – Chemical Bonding and Molecular Structure

Valence electrons, ionic bond, covalent bond, bond parameters, Lewis structure, polar character of covalent bond, covalent character of ionic bond, valence bond theory, resonance, geometry of covalent molecules, VSEPR theory, concept of hybridization, involving s, p and d orbitals and shapes of some simple molecules, molecular orbital theory of homonuclear diatomic molecules(qualitative idea only), Hydrogen bond.

UNIT V – Chemical Thermodynamics

Concepts of System and types of systems, surroundings, work, heat, energy, extensive and intensive properties, state functions. First law of thermodynamics – internal energy and enthalpy, measurement of U and H, Hess’s law of constant heat summation, enthalpy of bond dissociation, combustion, formation, atomization, sublimation, phase transition, ionization, solution and dilution. Second law of Thermodynamics (brief introduction)
Introduction of entropy as a state function, Gibb’s energy change for spontaneous and nonspontaneous processes.
Third law of thermodynamics (brief introduction).

UNIT VI – Equilibrium

Equilibrium in physical and chemical processes, dynamic nature of equilibrium, law of mass action, equilibrium constant, factors affecting equilibrium – Le Chatelier’s principle, ionic equilibrium- ionization of acids and bases, strong and weak electrolytes, degree of ionization,
ionization of poly basic acids, acid strength, concept of pH, hydrolysis of salts (elementary idea), buffer solution, Henderson Equation, solubility product, common ion effect (with illustrative examples).

UNIT VII – Redox Reactions

Concept of oxidation and reduction, redox reactions, oxidation number, balancing redox reactions, in terms of loss and gain of electrons and change in oxidation number, applications of redox reactions.

UNIT VIII – Organic Chemistry: Some basic Principles and Techniques

General introduction, classification and IUPAC nomenclature of organic compounds. Electronic displacements in a covalent bond: inductive effect, electromeric effect, resonance and hyper conjugation. Homolytic and heterolytic fission of a covalent bond: free radicals, carbocations, carbanions, electrophiles and nucleophiles, types of organic reactions.

UNIT IX – Hydrocarbons

Classification of Hydrocarbons
Aliphatic Hydrocarbons:
Alkanes – Nomenclature, isomerism, conformation (ethane only), physical properties, chemical reactions.
Alkenes – Nomenclature, structure of double bond (ethene), geometrical isomerism, physical properties, methods of preparation, chemical reactions: addition of hydrogen, halogen, water, hydrogen halides (Markovnikov’s addition and peroxide effect), ozonolysis, oxidation, mechanism of electrophilic addition.
Alkynes – Nomenclature, structure of triple bond (ethyne), physical properties, methods of preparation, chemical reactions: acidic character of alkynes, addition reaction of – hydrogen, halogens, hydrogen halides and water.

Aromatic Hydrocarbons:

Introduction, IUPAC nomenclature, benzene: resonance, aromaticity, chemical properties: mechanism of electrophilic substitution. Nitration, sulphonation, halogenation, Friedel Craft’s alkylation and acylation, directive influence of functional group in monosubstituted benzene. Carcinogenicity and toxicity.

To know the CBSE Syllabus for all the classes from 1 to 12, visit the Syllabus page of CBSE. Meanwhile, to get the Practical Syllabus of Class 11 Chemistry, read on to find out more about the syllabus and related information in this page.

CBSE Class 11 Chemistry Practical Syllabus with Marking Scheme

In Chemistry subject, practical also plays a vital role in improving their academic scores in the subject. The overall weightage of Chemistry practical mentioned in the CBSE Class 11 Chemistry syllabus is 30 marks. So, students must try their best to score well in practicals along with theory. It will help in increasing their overall academic score.

CBSE Class 11 Chemistry Practical Syllabus

The experiments will be conducted under the supervision of subject teacher. CBSE Chemistry Practicals is for 30 marks. This contribute to the overall practical marks for the subject.

The table below consists of evaluation scheme of practical exams.

Evaluation SchemeMarks
Volumetric Analysis08
Salt Analysis08
Content Based Experiment06
Project Work04
Class record and viva04
Total30

CBSE Syllabus for Class 11 Chemistry Practical

Micro-chemical methods are available for several of the practical experiments. Wherever possible such techniques should be used.

A. Basic Laboratory Techniques
1. Cutting glass tube and glass rod
2. Bending a glass tube
3. Drawing out a glass jet
4. Boring a cork

B. Characterization and Purification of Chemical Substances
1. Determination of melting point of an organic compound.
2. Determination of boiling point of an organic compound.
3. Crystallization of impure sample of any one of the following: Alum, Copper Sulphate, Benzoic Acid.

C. Experiments based on pH

1. Any one of the following experiments:

  • Determination of pH of some solutions obtained from fruit juices, solution of known and varied concentrations of acids, bases and salts using pH paper or universal indicator.
  • Comparing the pH of solutions of strong and weak acids of same concentration.
  • Study the pH change in the titration of a strong base using universal indicator.

2. Study the pH change by common-ion in case of weak acids and weak bases.

D. Chemical Equilibrium
One of the following experiments:

1. Study the shift in equilibrium between ferric ions and thiocyanate ions by increasing/decreasing the concentration of either of the ions.
2. Study the shift in equilibrium between [Co(H2O)6] 2+ and chloride ions by changing the concentration of either of the ions.

E. Quantitative Estimation
i. Using a mechanical balance/electronic balance.
ii. Preparation of standard solution of Oxalic acid.
iii. Determination of strength of a given solution of Sodium hydroxide by titrating it against standard solution of Oxalic acid.
iv. Preparation of standard solution of Sodium carbonate.
v. Determination of strength of a given solution of hydrochloric acid by titrating it against standard Sodium Carbonatesolution.

F. Qualitative Analysis
1) Determination of one anion and one cation in a given salt
Cations‐ Pb2+, Cu2+, As3+, Al3+, Fe3+, Mn2+, Ni2+, Zn2+, Co2+, Ca2+, Sr2+, Ba2+, Mg2+, NH4 +
Anions – (CO3)2‐ , S2‐, NO2‐ , SO32‐, SO2‐ , NO ‐ , Cl‐ , Br‐, I‐, PO43‐ , C2O2‐ ,CH3COO‐
(Note: Insoluble salts excluded)

2) Detection of ‐ Nitrogen, Sulphur, Chlorine in organic compounds.

G) PROJECTS
Scientific investigations involving laboratory testing and collecting information from other sources.

A few suggested projects are as follows:

  • Checking the bacterial contamination in drinking water by testing sulphide ion
  • Study of the methods of purification of water.
  • Testing the hardness, presence of Iron, Fluoride, Chloride, etc., depending upon the regional
    variation in drinking water and study of causes of presence of these ions above permissible
    limit (if any).
  • Investigation of the foaming capacity of different washing soaps and the effect of addition of
    Sodium carbonate on it.
  • Study the acidity of different samples of tea leaves.
  • Determination of the rate of evaporation of different liquids Study the effect of acids and
    bases on the tensile strength of fibres.
  • Study of acidity of fruit and vegetable juices.

Note: Any other investigatory project, which involves about 10 periods of work, can be chosen with the approval of the teacher.

Practical Examination for Visually Impaired Students of Class 11

Below is a list of practicals for the visually impaired students.

A. List of apparatus for identification for assessment in practicals (All experiments)
Beaker, tripod stand, wire gauze, glass rod, funnel, filter paper, Bunsen burner, test tube, test tube stand,
dropper, test tube holder, ignition tube, china dish, tongs, standard flask, pipette, burette, conical flask, clamp
stand, dropper, wash bottle
• Odour detection in qualitative analysis
• Procedure/Setup of the apparatus

B. List of Experiments A. Characterization and Purification of Chemical Substances
1. Crystallization of an impure sample of any one of the following: copper sulphate, benzoic acid
B. Experiments based on pH
1. Determination of pH of some solutions obtained from fruit juices, solutions of known and varied
concentrations of acids, bases and salts using pH paper
2. Comparing the pH of solutions of strong and weak acids of same concentration.

C. Chemical Equilibrium
1. Study the shift in equilibrium between ferric ions and thiocyanate ions by increasing/decreasing
the concentration of eitherions.
2. Study the shift in equilibrium between [Co(H2O)6]2+ and chloride ions by changing the
concentration of either of the ions.

D. Quantitative estimation
1. Preparation of standard solution of oxalic acid.
2. Determination of molarity of a given solution of sodium hydroxide by titrating it against standard
solution of oxalic acid.

E. Qualitative Analysis
1. Determination of one anion and one cation in a given salt
2. Cations – NH+4
Anions – (CO3)2-, S2-, (SO3)2-, Cl-, CH3COO-
(Note: insoluble salts excluded)
3. Detection of Nitrogen in the given organic compound.
4. Detection of Halogen in the given organic compound.

Note: The above practicals may be carried out in an experiential manner rather than recording observations.

We hope students must have found this information on CBSE Syllabus useful for their studying Chemistry. Learn Maths & Science in interactive and fun loving ways with ANAND CLASSES (A School Of Competitions) App/Tablet.

Frequently Asked Questions on CBSE Class 11 Chemistry Syllabus

Q1

How many units are in the CBSE Class 11 Chemistry Syllabus?

There are 9 units in the CBSE Class 11 Chemistry Syllabus. Students can access various study materials for the chapters mentioned in this article for free at ANAND CLASSES (A School Of Competitions).

Q2

What is the total marks for practicals examination as per the CBSE Class 11 Chemistry Syllabus?

The total marks for the practicals as per the CBSE Class 11 Chemistry Syllabus is 30. It includes volumetric analysis, content-based experiment, salt analysis, class record, project work and viva.

Q3

Which chapter carries more weightage as per the CBSE Syllabus for Class 11 Chemistry?

The organic chemistry chapter carries more weightage as per the CBSE Syllabus for Class 11 Chemistry.

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