UPSC Chemistry Syllabus 2026 for Paper 1 and 2

UPSC Chemistry Syllabus 2027 - Paper 1

Aspirants picking Chemistry as their optional subject can check the topics and subtopics on which the UPSC Chemistry Syllabus 2027 will be based on the following.

1. Solid State: Crystal systems; Designation of crystal faces, lattice structures and unit cell; Bragg's law; X-ray diffraction by crystals; Close packing, radius ratio rules, calculation of some limiting radius ratio values; Structures of NaCl, ZnS, CsCl, CaF2; stoichiometric and nonstoichiometric defects, impurity defects, semi-conductors.

2. Chemical bonding: Ionic bond, characteristics of ionic compounds, lattice energy, Born-Haber cycle; covalent bond and its general characteristics, polarities of bonds in molecules and their dipole moments; Valence bond 51 theory, concept of resonance and resonance energy; Molecular orbital theory (LCAO method); bonding H2 +, H2 He2 + to Ne2, NO, CO, HF, CN–, Comparison of valence bond and molecular orbital theories, bond order, bond strength and bond length.

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3. Liquid State: Kelvin equation; Surface tension and surface energy, wetting and contact angle, interfacial tension and capillary action.

4. Atomic Structure: Heisenberg's uncertainty principle, Schrodinger wave equation (time-independent); particle in one-dimensional box, Interpretation of wave function, quantum numbers, hydrogen atom wave functions; Shapes of s, p and d orbitals

5. Electrochemistry: Debye-Huckel theory of strong electrolytes and Debye-Huckel limiting Law for various equilibrium and transport properties. Galvanic cells, concentration cells; electrochemical series, measurement of e.m.f. of cells and their applications, fuel cells and batteries. Processes at electrodes; double layer at the interface; rate of charge transfer, current density; overpotential; electroanalytical techniques: amperometry, ion selective electrodes and their use.

6. The Gaseous State and Transport Phenomenon: Equation of state for real gases, intermolecular interactions, and critical phenomena and liquefaction of gases; Maxwell’s distribution of speeds, intermolecular collisions, collisions on the wall and effusion; Thermal conductivity and viscosity of ideal gases.

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7. Thermodynamics: Work, heat and internal energy; first law of thermodynamics.

Second law of thermodynamics; entropy as a state function, entropy changes in various processes, entropy-reversibility and irreversibility, Free energy functions; Thermodynamic equation of state; Maxwell relations; Temperature, volume and pressure dependence of U, H, A, G, Cp and Cv, and ; J-T effect and inversion temperature; criteria for equilibrium, relation between equilibrium constant and thermodynamic quantities; Nernst heat theorem, introductory idea of third law of thermodynamics.

8. Phase Equilibria and Solutions: Clausius-Clapeyron equation; phase diagram for a pure substance; phase equilibria in binary systems, partially miscible liquids—upper and lower critical solution temperatures; partial molar quantities, their significance and determination; excess thermodynamic functions and their determination.

9. Chemical Kinetics: Differential and integral rate equations for zeroth, first, second and fractional order reactions; Rate equations involving reverse, parallel, consecutive and chain reactions; Branching chain and explosions; effect of temperature and pressure on rate constant. Study of fast reactions by stop-flow and relaxation methods. Collisions and transition state theories.

10. Surface Phenomena and Catalysis: Adsorption from gases and solutions on solid adsorbents; Langmuir and B.E.T. adsorption isotherms; determination of surface area, characteristics and mechanism of reaction on heterogeneous catalysts.

11. Main Group Chemistry: Boranes, borazines, phosphazenes and cyclic phosphazene, silicates and silicones, Interhalogen compounds; Sulphur—nitrogen compounds, noble gas compounds.

12. General Chemistry of ‘f’ Block Element: Lanthanides and actinides: separation, oxidation states, magnetic and spectral properties; lanthanide contraction.

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13. Coordination Chemistry :

(i) Bonding in the transition of metal complexes. Valence bond theory, crystal field theory and its modifications; applications of theories in the explanation of magnetism and electronic spectra of metal complexes.

(ii) Isomerism in coordination compounds; IUPAC nomenclature of coordination compounds; stereochemistry of complexes with 4 and 6 coordination numbers; chelate effect and polynuclear complexes; trans effect and its theories; kinetics of substitution reactions in square-planar complexes; thermodynamic and kinetic stability of complexes.

(iii) EAN rule, Synthesis structure and reactivity of metal carbonyls; carboxylate anions, carbonyl hydrides and metal nitrosyl compounds.

(iv) Complexes with aromatic systems, synthesis, structure and bonding in metal olefin complexes, alkyne complexes and cyclopentadienyl complexes; coordinative unsaturation, oxidative addition reactions, insertion reactions, fluxional molecules and their characterisation; Compounds with metal—metal bonds and metal atom clusters.

14. Photochemistry: Absorption of light; decay of the excited state by different routes; photochemical reactions between hydrogen and halogens, and their quantum yields.

15. Main Group Chemistry: Interhalogen compounds, Boranes, phosphazenes and cyclic phosphazene, borazines, silicates and silicones, Sulphur—nitrogen compounds, noble gas compounds.

16. General Chemistry of ‘f’ Block Element: Lanthanides and actinides: separation, oxidation states, magnetic and spectral properties; lanthanide contraction.

17. Bio-inorganic chemistry: Metal ions in biological systems and their role in ion-transport across the membranes (molecular mechanism), oxygen-uptake proteins, cytochromes and ferredoxins.

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UPSC Chemistry Syllabus 2027 - Paper 2

As per the UPSC Chemistry 2027 Syllabus, Paper 2 will be based on the topics and subtopics as mentioned below:

1. (i) Reaction mechanisms: General methods (both kinetic and non-kinetic) of study of mechanisms or organic reactions: isotopies, method crossover experiment, intermediate trapping, stereochemistry; the energy of activation; kinetic control of reactions and thermodynamic control

(ii) Reactive intermediates: Generation, stability and reactions of Carbenium ions and carbanions, geometry, carbenes, free radicals, benzynes and nitrenes.

(iii) Substitution reactions:—SN 1, SN 2, and SNi, mechanisms; neighbouring group participation; electrophilic and nucleophilic reactions of aromatic compounds, including heterocyclic compounds—pyrrole, furan, thiophene and indole.

(iv) Elimination reactions:— E1, E2 and E1cb mechanisms; orientation in E2 reactions—Saytzeff and Hoffmann; Chugaev and Cope eliminations, pyrolytic syn elimination—acetate pyrolysis.

(v) Addition reactions:— ed olefins and carbonyls.

(vi) Reactions and Rearrangements:—(a) Beckmann, Hoffmann, Pinacol-pinacolone, Fries, Baeyer-Villiger, Claisen, Favorskii, Cope, Stevens and Wagner—Meerwein rearrangements.

(b) Aldol condensation, Perkin, Dieckmann, Knoevenagel, Clemmensen, Claisen condensation, Witting, Wolff-Kishner, Cannizzaro and von Richter reactions; Stobbe, benzoin and acyloin condensations; Skraup synthesis, Fischer indole synthesis, Reformatsky reactions and Sandmeyer and Bischler-Napieralski, Reimer-Tiemann.

2. Delocalised Covalent Bonding: Anti-aromaticity; azulenes, aromaticity, annulenes, tropolones, sydnones, fulvenes.

3. Pericyclic reactions: Classification and examples; Woodward-Hoffmann

rules—electrocyclic reactions, cycloaddition reactions [2+2 and 4+2] and sigmatropic

shifts [1, 3; 3, 3 and 1, 5], FMO approach.

4. Synthetic Uses of Reagents: HlO4, CrO3, OsO4, Pb(OAc)4, NBS, SeO2, B2H6, Na-Liquid NH3, NaBH4, LiAIH4, n-BuLi, MCPBA.

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5. Spectroscopy: Principles and applications in structure elucidation :

(i) Rotational—Diatomic molecules; rotational constants and isotopic substitution.

(ii) Vibrational—Diatomic molecules, specific frequencies of functional groups in polyatomic molecules and linear triatomic molecules.

(iii) Electronic—Singlet and triplet states. Conjugated double bonds and conjugated carbonyls: Woodward-Fieser rules; Charge transfer spectra.

(iv) Nuclear Magnetic Resonance (1HNMR): Basic principle, coupling constants, chemical shift and spin-spin interaction.

(v) Mass Spectrometry:— McLafferty rearrangement, metastable peak, Parent peak, base peak.

6. (i) Preparation and Properties of Polymers: polyvinyl chloride, polystyrene, Organic polymers, polyethene, synthetic, natural rubber, Teflon, nylon and terylene,

(ii) Biopolymers: Structure of proteins, RNA and DNA.

7. Photochemistry: Photochemical reactions of simple organic compounds, excited and ground states, singlet and triplet states, Norrish-Type I and Type II reactions.

UPSC Chemistry Syllabus 2027 - Preparation Tips

Aspirants planning to appear for UPSC IAS 2027 must do so in a better way, especially considering the tight competitiveness. Here we are sharing some IAS exam preparation tips that will be handy for candidates and help them score well and qualify for the UPSC 2027 exam. Check the tips here.

• Only refer to the NCERT books to prepare for Chemistry.

• Make a perfect IAS study plan 2027 and stick to it.

• UPSC CSE Chemistry requires a high level of preparation, and the difficulty level is at the graduation level, candidates must start the preparations early.

• Solve previous year's question papers of the Chemistry mains exam to know about the type of questions that are asked in the exam. Also, look for UPSC IAS question papers for Chemistry and solve mocks.

• Do the previous year's UPSC IAS exam analysis 2027, to know about the difficulty level of the exam, question trends and also to work on your weaker subjects.

UPSC Chemistry Syllabus 2027 Best Books

From the following table, check the list of best books for UPSC IAS preparation.

Best Books for Chemistry

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