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 ↓


Biodegradable and non-biodegradable polymers


Polymers are large molecules made up of repeated sub-units, known as monomers. They play a vital role in everyday life, making up materials ranging from plastic bottles to containers and the tyres of our cars. However, their varying ability to break down in the environment is a key difference that classifies them into two major categories: biodegradable and non-biodegradable polymers.

What are polymers?

Polymers are substances that consist of large molecules containing repeating structural units called monomers. These monomers are linked together in long chains. Polymers are known for their diverse properties and uses, ranging from synthetic plastics to natural proteins.

Chemical Structure Example: 
    - Polyethylene: -( CH2 -CH2 )- n
    - Polypropylene: -(C 3 H 6 )- n

Biodegradable polymer

Biodegradable polymers are polymers that can be decomposed by the action of living organisms, usually bacteria. They break down into natural by-products such as water, carbon dioxide and biomass. These polymers help reduce the problem of waste and pollution.

How biodegradable polymers work

The decomposition of biodegradable polymers occurs primarily through microbial action. Microorganisms digest the polymer, breaking the polymer back down into its component monomers or converting it into a simpler form that they can assimilate.

Examples of biodegradable polymers

  • Polylactic acid (PLA): A polymer derived from fermented plant starch (usually corn). Used in a variety of applications such as biodegradable medical implants, disposable utensils, and food packaging.
  • Polycaprolactone (PCL): Another synthetic biodegradable polymer often used in medical devices and controlled drug delivery systems.
  • Polyhydroxyalkanoates (PHAs): These are biodegradable plastics derived from bacterial fermentation. They can be used in packaging materials, agricultural films, and disposable items.
PLA Polymerization Reaction: 
    C 3 H 6 O 3 (lactic acid) ⟶ [-C(CH 3 )HC(=O)O-] n (polylactic acid)

Applications and benefits

Biodegradable polymers are integral to sustainable practices as they have the ability to decompose, thereby reducing pollution and waste creation. Their applications span across a variety of sectors:

  • Medical industry: Used in surgical sutures, drug delivery systems, and temporary implants such as stents and bone stabilization devices.
  • Agriculture: Biodegradable films can be used as mulch films, which decompose and enrich the soil instead of turning into waste.
  • Packaging: Used for packaging materials that reduce the environmental waste footprint.

Visual example

Biodegradable

Non-biodegradable polymers

Non-biodegradable polymers do not decompose naturally and therefore persist for a long time in the environment. These generally refer to most synthetic plastics used today. Their accumulation poses serious environmental challenges, contributing to pollution and landfill overflows.

How non-biodegradable polymers persist

Most non-biodegradable polymers such as polyethylene (PE) and polypropylene (PP) do not decompose naturally under the influence of microorganisms. This resistance to decomposition is due to their long, stable polymer chains, which are not easily damaged by environmental conditions.

Examples of non-biodegradable polymers

  • Polyethylene (PE): Widely used in plastic bags, bottles and containers. Highly resistant to environmental degradation.
  • Polyvinyl chloride (PVC): Used in pipes, cables and as a building material. It is known for its durability and flexibility.
  • Polystyrene (PS): Often used in Styrofoam packaging, insulation, and disposable cups. It takes hundreds of years to decompose.
Polyethylene Structure: 
    [-CH 2 -CH 2 -] n

Challenges and disadvantages

The persistence of non-biodegradable polymers in the environment causes several problems:

  • Environmental pollution: Accumulation in landfills and the natural environment causes pollution.
  • Threats to wildlife: Animals can ingest plastic waste or become entangled in it.
  • Resource consumption: Production depends on non-renewable fossil fuels.

Visual example

Non-bio

Conclusion

The difference between biodegradable and non-biodegradable polymers is essential to understand their environmental impact. Biodegradable polymers offer more sustainable solutions, decomposing naturally and reducing pollution. However, non-biodegradable polymers, while offering durability and convenience, pose significant environmental challenges due to their persistence.

Efforts to replace non-biodegradable materials with biodegradable alternatives remain crucial to maintain a balance between human needs and environmental protection.

Summary comparison

Biodegradable Polymer:
  • Decomposes naturally.
  • Environment friendly.
  • Often obtained from renewable resources.
Non-biodegradable polymers:
  • Persists in the environment.
  • This creates problems of pollution and waste.
  • Usually derived from fossil fuels.

Future perspectives

Research and innovation are crucial to develop more efficient biodegradable polymers and to optimize their production to meet industrial demands. Meanwhile, recycling and improved waste management for non-biodegradable polymers are essential to reduce their environmental footprint.

By understanding and acting upon the unique properties and effects of biodegradable and nonbiodegradable polymers, society can better address environmental concerns and promote sustainable practices.


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Biodegradable and non-biodegradable polymers

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