Grade 11
  1. Basic concepts of chemistry  1.1. Importance of Chemistry  1.2. Nature and scope of chemistry  1.3. laws of chemical combination  1.3.1. Law of conservation of mass  1.3.2. Law of definite proportions  1.3.3. Law of multiple proportions  1.3.4. Law of gaseous volume  1.3.5. Avogadro's Law  1.4. Dalton's atomic theory  1.5. Mole concept and molar mass  1.6. Percent composition  1.7. Empirical and molecular formula  1.8. Stoichiometry and Stoichiometric Calculations  1.9. Limiting reagent concept
  2. Structure of the atom  2.1. Discovery of the electron, proton, and neutron  2.2. Atomic Model  2.2.1. Thomson's model  2.2.2. Rutherford's model  2.2.3. Bohr's model  2.3. Quantum mechanical model of the atom  2.4. Dual nature of matter and radiation  2.5. Heisenberg's uncertainty principle  2.6. Quantum numbers  2.7. Atomic orbitals and their shapes  2.8. Electronic configuration of elements  2.9. Aufbau principle  2.10. Pauli's exclusion principle  2.11. Hund's maximum multiplicity rule  2.12. de Broglie's hypothesis  2.13. Photoelectric effect
  3. Classification of elements and periodicity in properties  3.1. Historical development of the periodic table  3.2. Modern Periodic Law and Periodic Table  3.3. Periodic trends in properties  3.3.1. Atomic and Ionic Radius  3.3.2. Ionization enthalpy  3.3.3. Electron gain enthalpy  3.3.4. Electronegativity  3.3.5. Valency  3.3.6. Metallic and Non-Metallic Properties  3.3.7. Oxidation states  3.4. Unusual Properties of the First Elements
  4. Chemical Bonding and Molecular Structure  4.1. Kossel–Lewis approach to chemical bonding  4.2. Ionic or electrovalent bond  4.3. Covalent bond and its features  4.4. Bond parameters  4.5. VSEPR Theory  4.6. Valence bond theory  4.7. Hybridization and its types  4.8. Molecular orbital theory  4.8.1. Bond order and stability  4.9. Hydrogen bonding
  5. States of matter  5.1. Intermolecular forces  5.2. Gas Laws  5.2.1. Boyle's law  5.2.2. Charles's Law  5.2.3. Avogadro's Law  5.2.4. Dalton's law of partial pressure  5.2.5. Graham's law of spread  5.3. Ideal Gas Equation and Applications  5.4. Real gases and deviations from ideal behaviour  5.5. Kinetic molecular theory of gases  5.6. Liquefaction of gases  5.7. Properties of Liquids  5.8. Surface tension and viscosity
  6. Thermodynamics  6.1. System and environment  6.2. Types of systems in thermodynamics  6.3. Types of procedures  6.4. First law of thermodynamics  6.5. Internal energy and enthalpy  6.6. Heat capacity and specific heat  6.7. Hess's law of constant heat summation  6.8. Bond dissociation enthalpy  6.9. Enthalpy of formation and combustion  6.10. Enthalpy of solution and neutralization  6.11. Spontaneity and the second law of thermodynamics  6.12. Gibbs free energy and its applications
  7. Balance  7.1. The concept of balance  7.2. Equilibrium constant and its applications  7.3. Le Chatelier's principle  7.4. Ionic equilibrium in solutions  7.5. Acid and Base Theory  7.5.1. Arrhenius concept  7.5.2. Bronsted-Lowry concept  7.5.3. Lewis concept  7.6. pH Scale and pOH  7.7. Common ion effect  7.8. Hydrolysis of salts  7.9. Buffer solutions and their mechanism of action  7.10. Solubility equilibrium of sparingly soluble salts
  8. Redox reactions  8.1. Oxidation and reduction concepts  8.2. Oxidation number and its applications  8.3. Redox reactions in terms of electron transfer  8.4. Balancing redox reactions (oxidation number and ion-electron methods)  8.5. Types of redox reactions  8.6. Electrochemical Cells and Redox Reactions
  9. Hydrogen  9.1. Position of Hydrogen in the Periodic Table  9.2. Isotopes of hydrogen  9.3. Preparation of Hydrogen  9.4. Properties of Hydrogen  9.5. Hydrides and their classification  9.6. Water and heavy water  9.7. Hydrogen peroxide and its properties  9.8. Uses of Hydrogen and Its Compounds
  10. S-block elements (alkali and alkaline earth metals)  10.1. Group 1 Elements - Properties and Trends  10.2. Group 2 Elements - Properties and Trends  10.3. Unusual properties of lithium and beryllium  10.4. Important compounds of sodium and their uses  10.5. Important Compounds of Magnesium and Calcium
  11. Some p-block elements  11.1. General Introduction to p-Block Elements  11.2. Group 13 Elements  11.2.1. Boron and its compounds  11.3. Group 14 Elements  11.3.1. Carbon and its allotropes  11.3.2. Important Compounds of Carbon and Silicon
  12. Organic Chemistry - Some Basic Principles and Techniques  12.1. Classification and Nomenclature of Organic Compounds  12.2. Structural representation of organic compounds  12.3. Classification of organic reactions  12.4. Electronic Effects in Organic Chemistry  12.4.1. Inductive effect  12.4.2. Resonance effect  12.4.3. Hyperconjugation  12.5. Reaction mechanism and intermediate species  12.6. Purification and qualitative analysis of organic compounds
  13. Hydrocarbons  13.1. Hydrocarbons  13.1.1. Preparation and Properties of Alkenes  13.2. alkene  13.2.1. Preparation and Properties of Alkenes  13.2.2. Electrophilic addition reactions  13.3. Alkynes  13.3.1. Preparation and Properties of Alkynes  13.4. Aromatic hydrocarbons  13.4.1. Structure and properties of benzene  13.4.2. Electrophilic substitution reactions of benzene
  14. Environmental Chemistry  14.1. Environmental Pollution  14.2. Atmospheric pollution and the greenhouse effect  14.3. Water pollution and treatment methods  14.4. Soil pollution and its effects  14.5. Industrial waste and its treatment  14.6. Strategies for pollution control

Grade 11 → Some p-block elements → Group 13 Elements ↓


Boron and its compounds


Boron is a fascinating element that belongs to group 13 of the periodic table. Group 13 elements are characterized by the presence of three electrons in their outermost shell. In this section, we will explore the properties, uses, and compounds of boron, highlighting its role in chemistry and materials science. Boron is unique because it exhibits properties of both metals and nonmetals, making it a metalloid, and it is important in the formation of a variety of compounds with complex structures.

Properties of Boron

Boron is represented by the symbol B and has an atomic number of 5. Its atomic mass is about 10.81 u. In its elemental form, boron is not found freely in nature, but it is available in compounds such as borax and boric acid.

Boron is hard and has a very high melting point, making it useful for high-temperature applications. It is a poor conductor of electricity at room temperature but becomes a good conductor at high temperatures. This unique behavior is due to its electron-deficient nature and complex crystal lattice.

Visualization of the structure of boron

B

The above illustration shows the basic structure of boron in its lattice, where it forms covalent bonds, which give it its hardness and high melting point properties.

Boron compounds

Boron forms a variety of compounds that have important industrial and medical applications. These compounds exhibit diverse chemical behavior and are essential in glassmaking, agriculture, and even nuclear reactors due to their neutron-absorbing properties.

Borax - Na 2 B 4 O 7 ·10H 2 O

Borax or sodium borate is one of the most well-known boron compounds. This compound is used mainly in cleaning products and as a buffering agent. It can soften water and has mild antiseptic properties.

Na 2 B 4 O 7 10H 2 O + 7H 2 O -> 2NaOH + 4H 3 BO 3

The equation above shows the hydrolysis of borax, resulting in the formation of sodium hydroxide and boric acid. This reaction occurs when borax is dissolved in water.

Boric Acid - H 3 BO 3

Boric acid is widely used as an antiseptic, insecticide, fire retardant, and in the manufacture of glass and ceramics. It is a weak acid and is often used in topical medical applications due to its bactericidal properties.

H 3 BO 3 <-> B(OH) 3

Understanding its structure

H H H

The geometry of boric acid is planar, with the boron atom bonded to three hydroxyl groups. This forms a trigonal planar structure which is responsible for its weak acidic nature. This geometry is important in the formation of hydrogen bonds when dissolved in water, which makes its aqueous solution more stable.

Boron Trioxide - B 2 O 3

Boron trioxide is another important compound of boron. It is used primarily in the production of borosilicate glass, which is highly heat resistant and commonly used in laboratory glassware and cookware.

B 2 O 3 + 3H 2 O -> 2B(OH) 3

When boron trioxide reacts with water, boric acid is formed, showing the interrelationship between different boron compounds.

Diborane - B 2 H 6

Diborane is a compound with a unique bond having electron-deficient bonds. It is highly reactive and is used as a reducing agent and as a starting material for the synthesis of other boron compounds.

Illustration of the structure of diborane

B B H H

The diborane structure consists of two boron atoms linked by shared hydrogen atoms, forming a "banana bond" or three-center two-electron bond, a distinctive feature of boron.

Applications of Boron and its compounds

Boron and its compounds are used in many ways in various industries. Here are some notable applications:

  • Glass and ceramics: Boron compounds are important in the manufacture of borosilicate glasses and ceramics due to their high temperature resistance and durability.
  • Agriculture: Boron is an essential micronutrient for plants; it plays an important role in cell wall strength and reproductive development.
  • Detergent: Borax is used in laundry detergents and household cleaners due to its cleaning and antiseptic properties.
  • Nuclear reactors: Compounds such as boron carbide serve as control rods due to their neutron absorption capability.

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Boron and its compounds

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