The elements of Group 17 from top to bottom are fluorine, chlorine, bromine, iodine, and astatine. They are referred to as halogens because they create salt. This group’s members are very similar to one another. They have a consistent pattern of physical and chemical features. The valence shell of each of these elements contains seven electrons. Their electronic setup is ns2 np5.

Oxoacids of Halogens-Properties, Structure,Hypochlorous Acid, Chlorous Acid, Perchloric Acid, Interhalogen Compounds, FAQs

by

The elements of Group 17 from top to bottom are fluorine, chlorine, bromine, iodine, and astatine. They are referred to as halogens because they create salt. This group’s members are very similar to one another. They have a consistent pattern of physical and chemical features. The valence shell of each of these elements contains seven electrons. Their electronic setup is ns2 np5.

If the acid contains oxygen (referred to as an oxoacid), the suffixes –ous and –ic are used again to signify the lower and larger number of oxygens in the acid formula. Oxoacids are composed of hydrogen, oxygen, and other elements. Acids that contain hydrogen, oxygen, and another element are known as oxyacids.

Group 17 Elements: The Halogen Family

Group 17 is the sixth p-block element group. The term Halogens is derived from the Greek words Halo and genes. Halogen is derived from the words halo, which means salt, and genes, which means born, so halogen implies salt producers. When interacting with alkali metals or alkali earth metals, all elements in group 17 create salts. As a result, this group is also known as the Halogen family, and the elements in this group are known as halogens.

Oxoacids of Halogens

Fluorine, chlorine, bromine, iodine, and astatine are all members of Group 17. They are collectively referred to as halogens, which means salt makers. This group’s members are strikingly similar. As we progress down the group, there is a consistent gradation in physical and chemical properties. We can’t separate them in their pure form. In an aqueous solution, they are stable. They are also extremely stable in salt form. Hypohalous acids (+1 oxidation state), halous acids (+3 oxidation state), halic acids (+5 oxidation state), and perhalic acids (+7 oxidation state) are the four types of oxoacids produced by halogens.

Astatine is the group’s lone radioactive element. Their valence shell has seven electrons (ns2 np5), one less than the next noble gas configuration. Because of their effective nuclear charge, halogens have a modest size. As a result, they are less likely to lose electrons and more likely to gain an electron to complete their octet. Several oxoacids are formed by halogens (they are acids that contain oxygen in the acidic group).

Properties of Halogen Oxoacids

  1. Fluorine is quite tiny and has a high electronegativity. As a result, it only produces one oxoacid, HOF, which is also known as fluoric(I) acid or hypofluorous acid. The other members of the halogen family combine to generate a number of oxoacids. They can’t be isolated in their pure form. They are stable in aqueous solutions or as salts.
  2. In general, halogens generate four types of oxoacids: hypohalous acids (+1 oxidation state), halous acids (+3 oxidation state), halic acids (+5 oxidation state), and perhalic acids (+7 oxidation state).
  3. Chlorine may be broken down into four types of oxoacids. That is, HOCl (hypochlorous acid), HOClO (chlorous acid), HOClO2 (chloric acid), and HOClO3 (hypo chloric acid) (perchloric acid).
  4. Bromine produces HOBr (hypobromous acid), HOBrO2 (bromic acid), and HOBrO3 (hypobromous acid) (perbromic acid). Iodine decomposes into HOI (hypoiodous acid), HOIO2 (iodic acid), and HOIO3 (hypoiodic acid) (periodic acid).

Structures of the oxoacids of halogens

The core halogen atom is sp3 hybridized in all oxoacids. Every oxoacid contains at least one X-OH bond. “X=O” linkages are present in the majority of these oxoacids. In nature, the double bond between the central halogen atom and oxygen in an oxoacid is d pi – p pi. Hypofluorous acid, hypochlorous acid, hypobromous acid, and hypoiodous acid are examples of hypohalous acids. In hypohalous acids, the halogen has an oxidation state of +1. Because of the existence of three lone pairs of electrons on the central halogen atom, the hypohalite ions have a linear form.

The elements of Group 17 from top to bottom are fluorine, chlorine, bromine, iodine, and astatine. They are referred to as halogens because they create salt. This group’s members are very similar to one another. They have a consistent pattern of physical and chemical features. The valence shell of each of these elements contains seven electrons. Their electronic setup is ns2 np5.

Hypochlorous Acid

Because hypohalous acids are less stable, they tend to create halic acids.

3HOX → HOXO2 + 3HX

Only fluorine oxoacid is hypofluorous acid. Due to the lack of d orbitals in the fluorine atom, no higher oxoacid of fluorine is known. Only chlorous acid is included in the halous acids. The oxidation state of chlorine in chlorous acid is +3. Because of the existence of two lone pairs on the core chlorine atom, the chlorite ion displays a V shape. Chloric acid, bromic acid, and iodic acid are examples of halic acids. In these oxoacids, the halogen has an oxidation state of +5. Because of the presence of a lone pair of electrons on the central halogen atom, the halite ions have a pyramidal structure.

The elements of Group 17 from top to bottom are fluorine, chlorine, bromine, iodine, and astatine. They are referred to as halogens because they create salt. This group’s members are very similar to one another. They have a consistent pattern of physical and chemical features. The valence shell of each of these elements contains seven electrons. Their electronic setup is ns2 np5.

Chlorous Acid

Perchloric acid, perbromic acid, and periodic acid are examples of perhalic acids. The halogen oxidation state of these oxoacids is +7. The perhalate ion has a tetrahedral structure. The first member of any sequence of halogen oxoacids has high acidic strength. This is because the halogens have a strong electro-negativity and are tiny in size.

The elements of Group 17 from top to bottom are fluorine, chlorine, bromine, iodine, and astatine. They are referred to as halogens because they create salt. This group’s members are very similar to one another. They have a consistent pattern of physical and chemical features. The valence shell of each of these elements contains seven electrons. Their electronic setup is ns2 np5.

Chloric Acid

Perchloric Acid

Perchloric acid, for example, has a high acidic strength among perhalic acids. Because chlorine is more electronegative than bromine or iodine, the shared electron pair in a Cl-O bond is closer to chlorine than bromine in a Br-O bond or iodine in an I-O bond. As a result, in the case of perchloric acid, the O-H bond becomes substantially weaker, allowing for the easy release of a proton. The acidic strength of an oxoacid grows as the halogen’s oxidation number increases.

The elements of Group 17 from top to bottom are fluorine, chlorine, bromine, iodine, and astatine. They are referred to as halogens because they create salt. This group’s members are very similar to one another. They have a consistent pattern of physical and chemical features. The valence shell of each of these elements contains seven electrons. Their electronic setup is ns2 np5.

Perchloric acid

Interhalogen Compounds

Interhalogen compounds are those that result from the reaction of two distinct halogens. They have general compositions of XX′, XX3′, XX5′, and XX7′, where X is a larger halogen and X′ is a smaller halogen, and X is more electropositive than X′. As the ratio of the radii of X and X′ grows, so does the number of atoms per molecule.

Sample Problems (FAQs)

Question 1: What are the uses of halogen?

Answer:

The following are some of the most prevalent applications for halogens:

  1. Fluorine compounds are commonly found in toothpaste and drinking water supplies. Fluorine is a very important drug because it is strongly reactive with tooth enamel and delays tooth decay.
  2. Chlorine is widely utilised in the bleaching process. It is also used in the metallurgy of gold and platinum.
  3. Chlorine is a chemical that is used to purify drinking water.
  4. Iodine is an antiseptic and a good germicide.

Question 2: What are interhalogen compounds?

Answer:

When halogens react with one another, interhalogen compounds are created. Their features and behaviours are midway between those of two-parent halogens. However, some features may differ. Except for IF7, all interhalogens can be created by mixing pure halogens under specific conditions.

Question 3: What are the oxidation states exhibited by halogens?

Answer:

The elements of the halogen family all have a -1 oxidation state. Fluorine, the most electronegative element, has only a -1 oxidation state. Elements with +1, +3, +5, and +7 states include chlorine, bromine, and iodine.

Question 4: How do halogens react with oxygen?

Answer:

When halogens react with oxygen, oxides are generated. However, it has been discovered that the oxides are unstable. In addition to oxides, halogens form a range of halogen oxoacids and oxoanions.

Question 5: Are halogens good oxidizing agents?

Answer:

The halogens are all excellent oxidizers. Fluorine is the most potent oxidizer on the list. It is capable of converting all halide particles to halogen.

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.

...

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.

© 2025 Anand Classes • Published by Anand Technical Publishers
Privacy Policy Terms Contact

Sitemap