UPSC Mains Chemistry Optional Syllabus (Paper I & Paper II) – Detailed Breakdown

The Chemistry optional is a highly scientific and logical subject in the UPSC Civil Services Mains Examination. Candidates with a background in Chemistry, Pharmacy, Chemical Engineering, or related fields often opt for this subject due to its scoring potential and clear-cut nature.

The syllabus is divided into Paper I and Paper II, each carrying 250 marks. Here’s a comprehensive, topic-wise descriptive breakdown of the syllabus.

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Paper I: Inorganic and Physical Chemistry

Section A – Inorganic Chemistry

Chemical Bonding and Molecular Structure

• Ionic Bonding: Factors affecting ionic bond strength, Born-Haber cycle, lattice energy.
• Covalent Bonding: Valence bond theory, molecular orbital theory (homonuclear and heteronuclear diatomic molecules), hybridization, VSEPR theory.
• Bond Parameters: Bond order, bond length, bond angle, and bond enthalpy.
• Coordinate Bonding & Metallic Bonding: Explanation through orbital overlap and band theory.

Solid State Chemistry

• Crystal Systems & Lattices: Unit cell, Bravais lattices, Miller indices, and crystal defects.
• X-ray Diffraction: Bragg’s law, determination of crystal structure.
• Types of Solids: Ionic, molecular, covalent network, and metallic solids.
• Imperfections: Point defects, dislocations, and their influence on properties.

Periodic Table and Periodicity

• Classification of Elements: Modern periodic law, long-form periodic table.
• Trends: Ionization energy, electron affinity, atomic/ionic radii, electronegativity.

Acids and Bases

• Arrhenius, Brønsted-Lowry, and Lewis concepts.
• HSAB principle (Hard and Soft Acids and Bases).
• pH calculations and acid-base equilibria in aqueous and non-aqueous solvents.

Environmental Chemistry

• Pollutants: Air, water, and soil pollution, greenhouse gases, and global warming.
• Chemical Reactions in Atmosphere: Photochemical smog, ozone depletion.
• Waste Management: Chemical treatment of industrial and nuclear waste.

Coordination Chemistry

• Werner’s Theory, Valence Bond Theory, and Crystal Field Theory.
• Isomerism: Structural and stereoisomerism in coordination compounds.
• Stability of Complexes: Thermodynamic and kinetic aspects.
• Spectral and Magnetic Properties: Electronic spectra and magnetic moments.

Bioinorganic Chemistry

• Role of metal ions in biological systems: Hemoglobin, myoglobin, and chlorophyll.
• Metalloproteins and metalloenzymes.
• Metal toxicity and metal deficiency diseases.

Lanthanides and Actinides

• Electronic configuration, oxidation states, color, and magnetic properties.
• Separation techniques and lanthanide contraction.
• Comparison of lanthanides and actinides.

Nuclear Chemistry

• Radioactivity: Types of decay, nuclear stability, and binding energy.
• Nuclear Reactions: Fission and fusion.
• Kinetics of radioactive decay and its applications in dating.

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Section B – Physical Chemistry

Atomic Structure

• Quantum theory, wave-particle duality, Schrödinger equation, quantum numbers.
• Hydrogen atom, radial and angular wave functions.
• Periodic properties in terms of quantum numbers.

Chemical Thermodynamics

• First, second, and third laws of thermodynamics.
• Gibbs and Helmholtz free energy.
• Criteria for spontaneity, partial molar quantities, chemical potential.

Chemical and Ionic Equilibrium

• Law of mass action, Le Chatelier’s Principle.
• Ionic equilibria in aqueous solutions – buffer, solubility product, common ion effect.

Solutions and Colligative Properties

• Raoult’s Law, ideal and non-ideal solutions.
• Determination of molecular weights from colligative properties.

Electrochemistry

• Conductance, electrochemical cells, Nernst equation.
• EMF, pH meters, concentration cells.
• Electrolysis and overpotential.

Chemical Kinetics

• Order and molecularity, rate laws, and integrated rate equations.
• Arrhenius equation, activation energy.
• Catalysis – homogeneous and heterogeneous.

Surface Chemistry

• Adsorption isotherms (Langmuir and Freundlich).
• Colloids, emulsions, micelles.
• Surfactants and detergents.

Quantum Chemistry

• Postulates of quantum mechanics.
• Operators, eigenfunctions and eigenvalues.
• Particle in a box and harmonic oscillator models.

Statistical Thermodynamics

• Concepts of microstates and macrostates.
• Boltzmann distribution, partition function.
• Application to ideal gases.

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Paper II: Organic Chemistry and Related Applications

Section A – Organic Chemistry

Basic Concepts in Organic Chemistry

• Inductive, mesomeric, hyperconjugation, and electromeric effects.
• Reactive intermediates: Carbocations, carbanions, free radicals, carbenes, nitrenes.
• Types of organic reactions: Substitution, addition, elimination, rearrangement.

Stereochemistry

• Geometrical and optical isomerism.
• Chirality, R/S and E/Z nomenclature.
• Conformational analysis of alkanes and cycloalkanes.

Reaction Mechanisms

• Mechanisms of SN1, SN2, E1, E2.
• Electrophilic and nucleophilic aromatic substitution.
• Addition to carbonyl groups, rearrangement reactions.

Named Reactions

• Aldol condensation, Cannizzaro, Perkin, Claisen, Wittig, etc.
• Detailed mechanism and synthetic utility of important named reactions.

Organic Synthesis

• Retrosynthetic analysis and synthetic strategies.
• Use of reagents like PCC, DCC, LiAlH4, NaBH4.
• Protecting groups and chemoselectivity.

Polymers

• Classification and methods of polymerization.
• Structure-property relationships.
• Biodegradable and conducting polymers.

Heterocyclic Chemistry

• Chemistry of five and six-membered heterocycles: Pyrrole, furan, thiophene, pyridine.
• Reactivity and synthesis of heterocycles.

Natural Products

• Alkaloids: Isolation, classification, and structural elucidation (e.g., nicotine, quinine).
• Terpenoids: Classification and biosynthesis.
• Vitamins and Hormones: Structural features and biological functions.

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Section B – Applied Organic Chemistry

Spectroscopy

• UV-Vis: λmax, chromophores, auxochromes.
• IR: Functional group identification.
• NMR: Chemical shift, spin-spin coupling.
• Mass Spectrometry: Fragmentation patterns and molecular ion peaks.

Photochemistry

• Jablonski diagram, fluorescence, phosphorescence.
• Photo-induced reactions and quantum yields.

Pericyclic Reactions

• Electrocyclic, cycloaddition, and sigmatropic rearrangements.
• Woodward-Hoffmann rules.

Organic Synthesis via Organometallics

• Grignard reagents, organolithium compounds.
• Applications in carbon-carbon bond formation.

Drugs and Medicinal Chemistry

• General principles of drug action.
• Structure-activity relationship (SAR).
• Synthesis of common drugs: Aspirin, paracetamol, sulfa drugs.

Biomolecules

• Carbohydrates: Classification, reactions, and stereochemistry.
• Proteins: Structure levels, peptide synthesis.
• Nucleic Acids: DNA, RNA – structure and function.
• Lipids: Fatty acids, triglycerides, and their biological roles.

Green Chemistry

• Principles and importance.
• Green solvents, catalysts, and alternative reaction conditions.
• Atom economy and sustainable chemical practices.

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Final Thoughts

The Chemistry Optional syllabus for UPSC Mains is comprehensive and technical, demanding a sound understanding of fundamental concepts and the ability to apply them in a descriptive and analytical manner. Aspirants should focus on:

• Clear concept-building through NCERTs and standard books (like Morrison & Boyd, JD Lee, Atkins).
• Diagrams and mechanisms wherever relevant.
• Previous year questions to understand the exam pattern.
• Regular revision and answer writing practice.