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


Polymers are everywhere around us and they play a vital role in our daily lives. From the plastics used in bottles and bags to the natural fibers used in clothing, polymers are an essential part of modern society. In chemistry, understanding polymers is important because they are used in countless applications, from industrial uses to everyday products.

What are polymers?

A polymer is a large molecule made up of repeating structural units. These units, known as monomers, are bonded together and form a long chain. The process of making a polymer from monomers is called polymerization. Polymers can be natural, such as cellulose found in plants, or synthetic, such as nylon and polyester.

Monomer → → polymer series

This diagram shows monomers joining together to form a polymer chain.

Types of polymers

Polymers can be classified into several types depending on their origin and synthesis:

Natural polymers

Natural polymers are found in nature and are essential for life. Examples of natural polymers include:

  • Proteins: These are made up of amino acid monomers. Proteins are important for the structure, function, and regulation of the body's cells, tissues, and organs.
  • Cellulose: A polysaccharide made from glucose monomers. It is an important component of plant cell walls and provides structural support.
  • DNA: Deoxyribonucleic acid, the molecule that carries genetic information in living organisms, is a polymer composed of nucleotides.

Synthetic polymers

Synthetic polymers are man-made polymers, created through chemical processes. Some common examples include:

  • Polyethylene: 
    -(CH2-CH2)n-
    It is the most common plastic, used in products such as plastic bags, bottles, and toys.
  • Polypropylene: 
    -(C3H6)n-
    It is known for its use in packaging, textiles and automotive components.
  • Polystyrene: 
    -(C8H8)n-
    Used in the production of disposable dinnerware, plastic models, and foam insulation.

Polymerization: How polymers are made

Polymerization is the process through which monomers are linked together to form a polymer. There are different types of polymerization, but the two main categories are addition polymerization and condensation polymerization.

Addition polymerization

In addition polymerization, monomers join each other without losing any atoms. This type of polymerization typically involves monomers with double bonds. An example of this is the polymerization of ethylene to form polyethylene.

Ethylene polyethylene

This diagram shows how ethylene molecules join together to form polyethylene, without losing any atoms in the process.

Condensation polymerization

In condensation polymerization, monomers join together and lose small molecules as byproducts, usually water, HCl, or methanol. This is typical of polyester and nylon synthesis.

Properties of polymers

The properties of polymers depend on their structure and composition. Factors that affect their properties include the type of monomers used, chain length, and cross-linking between chains. Some important properties of polymers that affect their functionality include:

  • Tensile strength: The resistance of a material to breaking under stress. Polymers can vary widely in tensile strength.
  • Elasticity: The ability of a polymer to return to its original shape after being stretched or compressed. Rubber is a classic example of an elastic polymer.
  • Thermal stability: This refers to how a polymer behaves at different temperatures. Some polymers melt easily, while others require higher temperatures to break down.
Dispersed polymer materials Basic form

This illustration shows a polymer that can be stretched and return to its original form, showing its elasticity.

Applications of polymers

Polymers have a wide range of applications due to their versatile properties. Here are some common uses:

In everyday products

  • Packaging materials: Polymers such as polyethylene and polypropylene are used extensively in packaging due to their lightweight and durable nature.
  • Textiles: Polyester, nylon and acrylic fibres are popular in the textile industry due to their strength and wear resistance.
  • Household items: Many kitchen utensils, furniture and toys are made from various plastics, highlighting the importance of polymers in our daily lives.

In technology and industry

  • Automotive parts: Polymers are increasingly being used in car parts to reduce weight, thereby improving fuel efficiency.
  • Electronics: Electrically conductive polymers are used in electronic devices such as displays, batteries, and solar cells.
  • Medical implants: Biodegradable polymers are used for sutures, bone fixation devices, and drug delivery systems.

Challenges and environmental impact

While polymers have revolutionized many aspects of modern life, they also present some challenges, especially with regard to the environment. Most synthetic polymers are not biodegradable, which contributes to the growing problem of plastic pollution.

Recycling is one solution to this problem, but it is not always straightforward due to the variety of polymers. Efforts are underway to develop alternative biodegradable polymers that may help reduce the environmental impact.

Repeat yourself

This symbol is associated with the recycling of polymer materials, which is an essential step to reduce environmental issues.

The future of polymers

As technology advances, new polymers with improved properties continue to be developed. Research is focused on creating polymers that are more durable, efficient, and suitable for a variety of applications. This includes everything from biodegradable plastics to advanced medical materials.

The future of polymers is very promising for innovation in materials science, and it offers solutions to some of the most important challenges facing society today.


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Polymer

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