Grade 12
  1. Solid state  1.1. Classification of solids  1.2. Crystal Lattice and Unit Cell  1.3. Packing Efficiency  1.4. Density of unit cell  1.5. Imperfections in solids (point and line defects)  1.6. Electrical Properties of Solids (Conductors, Insulators and Semiconductors)  1.7. Magnetic Properties of Solids (Diamagnetic, Paramagnetic and Ferromagnetic Materials)
  2. Solution  2.1. Types of Solutions (Homogeneous and Heterogeneous)  2.2. Expressing concentration of solutions (mass %, volume %, molarity, molality, normality, mole fraction)  2.3. Solubility of solids and gases in liquids (Henry's law)  2.4. Raoult's Law and Ideal and Non-Ideal Solutions  2.5. Syndrome properties  2.6. Abnormal molar mass and Van't Hoff factor
  3. Electrochemistry  3.1. Electrochemical cells (galvanic and electrolytic cells)  3.2. Galvanic cell and EMF of the cell  3.3. Standard electrode potential and electrochemical series  3.4. Nernst equation and its applications  3.5. Conductivity and electrolytic cells (specific, molar and equivalent conductivity)  3.6. Kohlrausch's law and its applications  3.7. Batteries (primary and secondary cells)  3.8. Corrosion and its prevention
  4. Chemical kinetics  4.1. Rate of chemical reaction  4.2. Factors affecting the reaction rate (concentration, temperature, catalyst, surface area)  4.3. Order and molecularity of the reaction  4.4. Integrated Rate Equations (Zero, First and Second Order)  4.5. Half-life of a reaction  4.6. Collision theory and activation energy  4.7. Arrhenius equation and its applications
  5. Surface chemistry  5.1. Adsorption and its types (Physicosorption and Chemisorption)  5.2. Catalysis and its types (homogeneous and heterogeneous)  5.3. Colloids and their properties (Tyndall effect, Brownian motion, coagulation)  5.4. Emulsions and gels  5.5. Applications of Colloids
  6. General principles and processes of separation of elements  6.1. Presence of metals and minerals  6.2. Concentration of ores (gravity separation, froth flotation, magnetic separation)  6.3. Extraction of raw metals (roasting, calcination, reduction)  6.4. Thermodynamic and electrochemical principles of metallurgy  6.5. Refining of metals
  7. P-block elements  7.1. Group 15 elements (nitrogen and phosphorus)  7.2. Group 16 Elements (Oxygen, Sulphur and their Compounds)  7.3. Group 17 Elements (Halogens and their Compounds)  7.4. Group 18 Elements  7.5. Properties and Trends in p-Block Elements  7.6. Important compounds of p-block elements (ammonia, phosphine, sulphuric acid, hydrochloric acid)  7.7. Interhalogen compounds and their applications
  8. d-block and f-block elements  8.1. General Properties of Transition Metals  8.2. Properties of Inner Transition Metals (Lanthanoids and Actinoids)  8.3. Lanthanoid and actinoid contractions  8.4. Coordination Chemistry of d-Block Elements
  9. Coordination compounds  9.1. Werner's theory and modern concepts  9.2. Coordination number and type of ligand  9.3. Nomenclature of Coordination Compounds  9.4. Isomerism (geometrical and optical) in coordination compounds  9.5. Bonding in Coordination Compounds (Valence Bond Theory and Crystal Field Theory)  9.6. Stability and applications of coordination compounds in medicine and industry
  10. Haloalkanes and haloarenes  10.1. Classification and nomenclature of haloalkanes and haloarenes  10.2. Physical and Chemical Properties of Haloalkanes and Haloarenes  10.3. Mechanism of Nucleophilic Substitution Reactions (SN1 and SN2)  10.4. Uses and environmental effects (ozone depletion, CFCs)
  11. Alcohol, phenol and ether  11.1. Structure and classification of alcohols, phenols and ethers  11.2. Preparation and properties of alcohols  11.3. Preparation and properties of phenol  11.4. Preparation and properties of ethers  11.5. Chemical Reactions and Uses
  12. Aldehydes, ketones and carboxylic acids  12.1. Structure and nomenclature in aldehydes, ketones and carboxylic acids  12.2. Preparation and properties of aldehydes and ketones  12.3. Chemical reactions in aldehydes, ketones and carboxylic acids (nucleophilic addition, oxidation and reduction)  12.4. Preparation and Properties of Carboxylic Acids  12.5. Chemical Reactions and Uses of Carboxylic Acids
  13. Nitrogen-containing organic compounds  13.1. Amines (classification, structure, basicity)  13.2. Preparation and properties of amines  13.3. Reactions of Amines (Diazotization, Carbylamine Reaction)  13.4. Diazonium salts and their applications in paint industry
  14.1. Carbohydrates (classification and properties)  14.2. Proteins (Structure and Function)  14.3. Enzymes (Mechanism and Function)  14.4. Nucleic acids (DNA and RNA)  14.5. Vitamins and hormones
  15. Polymer  15.1. Classification of Polymers (Addition, Condensation, Copolymers)  15.2. Types of polymerization (free radical, ionic, condensation)  15.3. Important Polymers and Their Uses  15.4. Biodegradable and non-biodegradable polymers
  16. Chemistry in Everyday Life  16.1. Drugs and their classification (analgesics, antipyretics, antibiotics, antacids)  16.2. Chemicals in food and cosmetics (preservatives, artificial sweeteners, antioxidants)  16.3. Cleaning agents and detergents (soaps, synthetic detergents, surfactants)  16.4. Environmental Chemistry (Pollution, Green Chemistry, Sustainable Chemistry)

Grade 12 → Polymer ↓


Classification of Polymers (Addition, Condensation, Copolymers)


In the world of chemistry, polymers play an essential role due to their versatile properties and diverse applications. A polymer is a large molecule composed of repeating structural units called monomers. Polymers can be classified in many ways based on their origin, structure, polymerization process, and physical properties. However, one of the most practical methods of classification is based on the polymerization mechanism, which includes addition (chain-growth) polymerization, condensation (step-growth) polymerization, and copolymers.

Addition polymerization

Addition polymerization, also known as chain-growth polymerization, occurs when monomers with double or triple bonds are joined together without losing any of the smaller molecules. This type of polymerization mainly involves monomers with unsaturated carbon-carbon bonds such as alkenes and alkynes.

Let us take the example of making polyethylene from ethylene monomers. In this process, the double bonds between the carbon atoms in the ethylene molecules open up and get linked together to form a long chain polymer. The visual representation of this process can be seen in the illustration below:

C=C + C=C + C=C → -CCCCCC-
CH2=CH2 , CH2=CH2 , CH2=CH2 -CH2-CH2-CH2-CH2-CH2-

Types of addition polymerization

Addition polymerization can be further classified into different mechanisms:

  • Free radical polymerization: A common type of addition polymerization uses free radicals to initiate the reaction. For example, polystyrene is made through this method.
  • Cationic polymerization: A cation is needed to start the polymerization process. An example of this is the polymerization of isobutylene to form butyl rubber.
  • Anionic polymerization: In this process, the anion initiates the polymerization. For example, poly(ethylene oxide) uses this method.

Condensation polymerization

Condensation polymerization, or step-growth polymerization, involves reactions between monomers with the elimination of small molecules, such as water, alcohol or hydrogen chloride. This type of polymerization usually involves monomers containing functional groups, such as alcohols, amines or carboxylic acids.

A classic example of condensation polymerization is the formation of nylon, a widely used synthetic polymer. Nylon is formed by the reaction between diamine and dicarboxylic acid. During this reaction, each bond formed results in the release of a water molecule as shown in the example below:

NH2-R-NH2 + HOOC-R'-COOH → [-NH-R-NHOC-R'-CO-] + H2O
NH2-R-NH2 , hook-r'-kooh [-NH-R-NHOC-R'-CO-] , H2O

Examples of condensation polymers

  • Polyesters: These are formed by the polycondensation of dicarboxylic acids and diols. A common example is polyethylene terephthalate (PET), which is used in plastic bottles.
  • Polyamide: As mentioned earlier, nylon is a type of polyamide made from diamine and dicarboxylic acid.
  • Polycarbonates: These are obtained by the reaction of bisphenol A and phosgene. They are used in making compact discs and safety glasses.

Copolymers

Copolymers are polymers made from two or more different types of monomers. The arrangement and distribution of these copolymers can give the resulting copolymers unique properties, making them widely useful in a variety of applications.

The arrangement of monomers in the copolymer chain may vary, and based on these arrangements, copolymers can be classified as follows:

  • Random copolymer: Here, two or more monomers are randomly distributed along the polymer chain. An example of this is the butadiene-styrene copolymer used in automobile tyres.
  • Alternating copolymers: The monomers are arranged in a regular alternating pattern. An example of this is the equimolar copolymer of maleic anhydride and styrene.
  • Block copolymers: These consist of large blocks of repeating units of each type of monomer. An example of this is styrene-butadiene-styrene (SBS), which is used in the production of shoe soles and tires.
  • Graft copolymers: These contain branches of one type of monomer grafted onto the main chain of another polymer. An example of this is grafting methyl methacrylate onto natural rubber to improve its properties.

Visual example of copolymer types

Random Copolymer: Alternating copolymer: Block Copolymer: Graft Copolymer:

Applications of copolymers

Copolymers are used in a variety of areas due to their unique properties:

  • Clothing: Copolymers increase the elasticity and strength of clothing, making them durable and comfortable.
  • Pharmaceuticals: These are used in drug delivery systems to control the release of the drug in the body.
  • Packaging: Copolymers provide superior barrier properties against gases and moisture, making them excellent for food packaging.
  • Automotive: Used in making tires, dashboards and upholstery for improved performance and aesthetics.

Conclusion

Classifying polymers based on the polymerization process and monomer arrangement is important in understanding their behavior and determining their applications. Addition polymerization provides a route to linear polymers with strong properties used in everyday plastic products. On the other hand, condensation polymerization leads to polymers such as nylon and polyester, which are essential in clothing and engineering materials. Copolymers provide versatile solutions by incorporating different monomers, allowing targeted properties for specific applications. Understanding these mechanisms and structures provides a basis for innovations and developments in polymer chemistry and applications in various industries.


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Classification of Polymers (Addition, Condensation, Copolymers)

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