Chemistry is offered as an optional subject in the UPSC civil services mains examination. It is the study of matter, its properties, composition, and the changes it undergoes. In addition, it covers topics that help in understanding how substances interact, the principles behind reactions, and the theoretical knowledge needed to explain chemical phenomena. In this article, we will look into the detailed UPSC Chemistry Optional Syllabus, along with the PDF to download.
UPSC Chemistry Optional Syllabus-Overview
There are two papers in the UPSC Chemistry Optional Syllabus. It covers a wide range of topics, including atomic structure, chemical bonding, thermodynamics, coordination chemistry, organic reaction mechanisms, and more. This paper of the UPSC syllabus Civil Services optional would be of 250 marks, totalling 500 marks. The time allowed for attempting each of them will be three hours. Each paper would have objective answer-type questions. There is no negative marking.
| Overview of UPSC Chemistry Optional Syllabus 2026 | |||
| Sl. No. | UPSC IAS Mains Papers | Subject | Marks |
| 1 | Paper VI | Optional Subject Paper-I | 250 |
| 2 | Paper VII | Optional Subject Paper-II | 250 |
| TOTAL | 500 | ||
| Time Duration | 3 hours | ||
Why Choose the Chemistry Optional Subject for UPSC?
There are a few reasons that suggest Chemistry is a good subject for the UPSC Exams:
1. A Simple and Static Syllabus: Firstly, the UPSC Chemistry optional syllabus is neatly divided into Physical, Organic, and Inorganic Chemistry. Unlike many humanities subjects, it remains stable over the years, making it easier for aspirants to plan their preparation.
2. High Scoring Potential: Second, Chemistry includes numerical problems and well-defined concepts. With accurate solutions, candidates can score high marks, unlike in subjective subjects, where answers may vary.
3. Less Competition as Compared to Many of the Popular Optionals: Third, compared to popular optionals, Chemistry has fewer takers in UPSC. This means reduced competition and a better chance of standing out with the right preparation. As per the UPSC 2020 Annual Report, Chemistry had 153 candidates appearing, out of which 15 were recommended, giving it a success rate of 9.8%. In 2021, the success rate improved further, with 127 aspirants appearing and 14 recommended, resulting in an 11.0% success rate.
4. Strong Conceptual and Analytical Approach: Fourth, the subject sharpens problem-solving and analytical skills. Practicing past UPSC questions in Chemistry also
indirectly helps in handling General Studies.
5. Overlap with Other Science-Based Subjects: However, Aspirants from engineering, physics, or medical streams often find the Chemistry syllabus more familiar and manageable.
6. Availability of Study Material and Notes: Also, Plenty of resources are available, including coaching notes, online study material, and guidance from previous toppers.
7. By analyzing past papers, candidates can identify high-value topics, making preparation more targeted.
8. Limited Subjectivity/Multidimensionality: The Chemistry optional course focuses on numerical problems, equations, and reactions, limiting subjectivity. This allows for precise evaluation and consistency in demonstrating abilities.
9. Less Answer-Writing: Unlike essay-heavy subjects, Chemistry requires concise, to-the-point answers. With good practice, completing the paper within time becomes easier.
10. Technical Services: Hence, a background in Chemistry can be helpful in technical services such as IRS or IDES, where scientific knowledge and research-based work are often involved.
UPSC Chemistry Optional Syllabus
The UPSC Chemistry Optional Syllabus is one of the most chosen options for Civil Services Exam students who have a proficiency in the subject or an Engineering background. The benefit of Chemistry as an optional subject is that the syllabus is structured to include Physical, Organic, and Inorganic Chemistry, allowing for both theoretical and practical learning.
The UPSC Chemistry Optional is divided into two papers, both of which assess candidates’ knowledge of core chemistry principles, reactions, mechanisms, and analytical techniques. Students who are thoroughly versed in the syllabus and frequently practice numericals and theory-based questions generally find Chemistry to be a good-scoring optional subject and manageable for the UPSC Mains Exam.
1. UPSC Chemistry Optional Syllabus: Paper 1
The Chemistry UPSC syllabus for optional paper 1 covers several significant and fundamental topics, including Physical Chemistry, which encompasses major areas such as Thermodynamics, Quantum Chemistry, and Chemical Kinetics. Furthermore, it mainly covers the fundamental axioms and theories that are important to know to comprehend chemical processes and reactions.
Below is a detailed view of the main topics of the UPSC Chemistry optional syllabus: Paper 1:
| Topic | Details |
| Atomic Structure | Heisenberg’s uncertainty principle, Schrödinger wave equation, quantum numbers, hydrogen atom wave functions, and shapes of s, p, and d orbitals. |
| Chemical Bonding | Ionic bonds, lattice energy, Born-Haber cycle, covalent bonds, polarities, resonance, molecular orbital theory, bond order, strength, and length. |
| Solid State | Crystal systems, lattice structures, Bragg’s law, X-ray diffraction, close packing, radius ratio rules, structures of NaCl, ZnS, CsCl, CaF2, defects, and semiconductors. |
| Gaseous State and Transport Phenomenon | Equation of state for real gases, intermolecular interactions, critical phenomena, Maxwell’s distribution, thermal conductivity, and viscosity. |
| Liquid State | Kelvin equation, surface tension, surface energy, wetting, contact angle, interfacial tension, and capillary action. |
| Thermodynamics | First and second laws, entropy, free energy functions, Maxwell relations, temperature, volume, pressure dependence, J-T effect, equilibrium, and Nernst heat theorem. |
| Phase Equilibria and Solutions | Clausius-Clapeyron equation, phase diagram, binary systems, partial molar quantities, excess thermodynamic functions. |
| Electrochemistry | Debye-Hückel theory, galvanic and concentration cells, electrochemical series, electrode processes, rate of charge transfer, and electroanalytical techniques. |
| Chemical Kinetics | Rate equations for various orders, reactions, temperature and pressure effects, fast reaction methods, collisions, and transition state theories. |
| Photochemistry | Light absorption, decay of excited states, photochemical reactions, and quantum yields. |
| Surface Phenomena and Catalysis | Adsorption isotherms, surface area determination, and reaction mechanisms on heterogeneous catalysts. |
| Bioinorganic Chemistry | Metal ions in biological systems, ion-transport, oxygen-uptake proteins, cytochromes, and ferredoxins. |
| Coordination Chemistry | Bonding theories, isomerism, nomenclature, stereochemistry, chelate effect, trans effect, substitution reactions, stability, metal carbonyls, and metal-aromatic complexes. |
| Main Group Chemistry | Boranes, borazines, phosphazenes, silicates, silicones, interhalogen compounds, sulfur-nitrogen compounds, noble gas compounds. |
| General Chemistry of ‘f’ Block Elements | Lanthanides and actinides: separation, oxidation states, magnetic and spectral properties, lanthanide contraction. |
2. UPSC Chemistry Optional Syllabus: Paper 2
The UPSC Chemistry Optional Syllabus: Paper 2 deals with Organic Chemistry, including the study of Organic Reaction Mechanisms.
| Topic | Subtopics |
| Delocalised Covalent Bonding | Aromaticity, anti-aromaticity; annulenes, azulenes, tropolones, fulvenes, sydnones. |
| Reaction Mechanisms | General methods (kinetic and non-kinetic): isotopic method, cross-over experiment, intermediate trapping, stereochemistry, energy of activation, thermodynamic and kinetic control of reactions. |
| Reactive Intermediates | Generation, geometry, stability, and reactions of carbonium ions, carbanions, free radicals, carbenes, benzynes, and nitrenes. |
| Substitution Reactions | SN1, SN2, and SNi mechanisms; neighbouring group participation; electrophilic and nucleophilic reactions of aromatic compounds (including heterocyclic compounds: pyrrole, furan, thiophene, and indole). |
| Elimination Reactions | E1, E2, and E1cb mechanisms; orientation in E2 reactions (Saytzeff and Hoffmann); pyrolytic syn elimination (Chugaev and Cope eliminations). |
| Addition Reactions | Electrophilic addition to C=C and C=C; nucleophilic addition to C=O, C=N, conjugated olefins, and carbonyls. |
| Reactions and Rearrangements | (a) Pinacol-pinacolone, Hoffmann, Beckmann, Baeyer-Villiger, Favorskii, Fries, Claisen, Cope, Stevens, and Wagner-Meerwein rearrangements. |
| (b) Aldol condensation, Claisen condensation, Dieckmann, Perkin, Knoevenagel, Wittig, Clemmensen, Wolff-Kishner, Cannizzaro, von Richter, Stobbe, benzoin, and acyloin condensations; Fischer indole synthesis, Skraup synthesis, Bischler-Napieralski, Sandmeyer, Reimer-Tiemann, and Reformatsky reactions. | |
| 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. |
| Preparation and Properties of Polymers | Organic polymers: polyethene, polystyrene, polyvinyl chloride, Teflon, nylon, terylene, synthetic and natural rubber. |
| Biopolymers | Structure of proteins, DNA, and RNA. |
| Synthetic Uses of Reagents | OsO4, HIO4, CrO3, Pb(OAc)4, SeO2, NBS, B2H6, Na-Liquid NH3, LiAlH4, NaBH4, n-BuLi, and MCPBA. |
| Photochemistry | Photochemical reactions of simple organic compounds; excited and ground states; singlet and triplet states; Norrish-Type I and Type II reactions. |
| Spectroscopy | (i) Rotational: Diatomic molecules; isotopic substitution and rotational constants. |
| (ii) Vibrational: Diatomic molecules, linear triatomic molecules, specific frequencies of functional groups in polyatomic molecules. | |
| (iii) Electronic: Singlet and triplet states; N→π* and π→π* transitions; application to conjugated double bonds and conjugated carbonyls (Woodward-Fieser rules); charge transfer spectra. | |
| (iv) Nuclear Magnetic Resonance (1H NMR): Basic principle; chemical shift, spin-spin interaction, and coupling constants. | |
| (v) Mass Spectrometry: Parent peak, base peak, metastable peak, McLafferty rearrangement. |
How to Prepare for the Chemistry Optional Paper for UPSC?
If you want to get ready for the Chemistry Optional paper in the UPSC (Union Public Service Commission) exam, you will need to have a good strategy and a strong work ethic. Adequate preparation of the UPSC Chemistry Optional Syllabus requires a strategic plan. Here is a full-fledged plan to help you prepare:
1. Understand the Syllabus: Read and understand the UPSC Chemistry Optional syllabus to get an idea of the important topics and to assess your preparation.
2. Refer to Standard Books: Use standard textbooks prescribed in undergraduate and postgraduate chemistry courses.
3. Attend Mock Tests: Take regular mock tests while following exam-like conditions and timing. You will not only know your current preparation status, but it will also help you to identify where to improve.
4. Make Short Notes: Make short notes while studying each topic that will help you in the last few days before the exam.
5. Conceptual Clarity: Rather than memorising concepts, focus on what you understand. This way, you can view questions from many approaches.
6. Current Affairs: Make sure you keep up-to-date with what is occurring in chemistry, especially current affairs relevant to the UPSC syllabus. It can include written research articles, inventions, discoveries, applications, etc
7. Revision: Make sure you have ample time for revision! Revise as many times as your syllabus allows. Revising and going over topics are essential to understanding and remembering them.
Conclusion
Chemistry has a great chance to be a high-scoring optional subject for you in the UPSC exam. With a proper plan, resources, and a little effort from your side, you can have a high score in Chemistry. You should cover the entire UPSC Chemistry optional syllabus, practice answer writing, and conduct thorough revision.
Are you getting ready for the UPSC 2025? Enroll in our SPM IAS Academy’s UPSC foundation batches to improve your readiness. Enrol right away!
Previous Years’ Question Papers
| 2024 Chemistry Optional Paper | |
| 2024 Chemistry Optional Paper- 1 | 2024 Chemistry Optional Paper- 2 |
| 2023 Chemistry Optional Paper | |
| 2023 Chemistry Optional Paper- 1 | 2023 Chemistry Optional Paper- 2 |
| 2022 Chemistry Optional Paper | |
| 2022 Chemistry Optional Paper- 1 | 2022 Chemistry Optional Paper- 2 |
| 2021 Chemistry Optional Paper | |
| 2021 Chemistry Optional Paper- 1 | 2021 Chemistry Optional Paper- 2 |
| 2020 Chemistry Optional Paper | |
| 2020 Chemistry Optional Paper- 1 | 2020 Chemistry Optional Paper- 2 |
| 2019 Chemistry Optional Paper | |
| 2019 Chemistry Optional Paper- 1 | 2019 Chemistry Optional Paper- 2 |
| 2018 Chemistry Optional Paper | |
| 2018 Chemistry Optional Paper- 1 | 2018 Chemistry Optional Paper- 2 |
| 2017 Chemistry Optional Paper | |
| 2017 Chemistry Optional Paper- 1 | 2017 Chemistry Optional Paper- 2 |
| 2016 Chemistry Optional Paper | |
| 2016 Chemistry Optional Paper- 1 | 2016 Chemistry Optional Paper- 2 |
Frequently Asked Questions
The UPSC Chemistry Optional syllabus includes two papers: Paper 1 on Physical and Inorganic Chemistry and Paper 2 on Organic Chemistry. It is stable and manageable for candidates.
Previous year question papers are vital for understanding the UPSC Chemistry Optional exam pattern, identifying key topics, and improving time management and confidence.
Chemistry Optional is a scoring subject because of its objective nature, numerical focus, and clear answers, allowing for high marks with systematic preparation.
Chemistry Optional UPSC notes are available from coaching institutes, online platforms, and toppers’ resources. Many aspirants prefer structured notes from sources like SPM IAS Academy for simplified explanations and quick revision.
Yes, Chemistry is a good UPSC optional for candidates with a science background due to its scoring potential and clear concepts.
According to data from the last five years, around 100 to 150 aspirants opt for the Chemistry optional, with a success rate hovering between 9% and 10%.
Mastering Chemistry demands a strong theoretical understanding and grasp of complex concepts, making it moderately challenging due to its broad and detailed syllabus.
Yes, Chemistry is considered a scoring subject in UPSC with focused preparation and clear conceptual understanding.
