Common questions
About the model answers, which papers and years are covered, the books and how to use the site.
About the solutions
What is VKC Science?
A site of solved previous-year papers for the UPSC exams that have a descriptive chemistry paper: Civil Services Mains (Chemistry optional), Combined Geo-Scientist (Chemist) and Indian Forest Service. It is run by Vimal Swarnkar (VKC), who writes the model answers.
Who writes the model answers?
Vimal Swarnkar (VKC): Integrated M.Sc. Chemistry from IIT Roorkee, CSIR NET Chemical Sciences All India Rank 4 (2019), a UPSC Civil Services Mains candidate with Chemistry optional and three times at the interview stage of the Combined Geo-Scientist exam. He has taught chemistry for competitive exams since 2019. See the mentor page.
How is each answer written?
As it would fit in an answer booklet: a labelled diagram or reaction scheme first, then a few short lines with the key words. The reaction type, intermediate, rate-determining step and stereochemistry are written on the scheme itself, so the answer stays short without losing content.
Are physical chemistry numericals worked out step by step?
Yes. Each numerical shows the governing equation, the values substituted with their units, and the result with its unit, followed by a line on what the number means.
Are organic reaction mechanisms drawn in full?
Yes. Mechanisms are drawn with curved arrows and labelled on the scheme: the reaction type, the intermediate, the slow step and the stereochemistry where it matters.
Coverage
Which papers and years are solved?
Combined Geo-Scientist Mains Chemistry Papers I, II and III for every year from 2016 to 2025; Civil Services Mains Chemistry Papers I and II and Indian Forest Service Chemistry Papers I and II for 2021 to 2025. Question papers can be downloaded for Civil Services, Geo-Scientist Mains and IFoS (2016 to 2025) and Geo-Scientist Prelims (2021 to 2026). The coverage table shows every paper and year.
Is 2020 covered?
For Geo-Scientist Mains, yes: Papers I, II and III are solved for 2016 to 2020 as well, so each paper has ten years solved. Civil Services and IFoS solutions start at 2021; older years may be added later, and new years are announced on Telegram first.
Are all sub-questions solved?
In the books, yes: every question of every paper, every part (eight per paper in Civil Services, ten in Geo-Scientist Paper III). On the site, Paper I has every question answered free. For Paper II and Geo-Scientist Papers II and III, the free solution answers a full attempt, the questions a candidate would choose (five in Civil Services, worth 250 of 400 marks; six in Geo-Scientist Paper I, ten in Paper II and six in Paper III); every other part has its own page with the question text and is answered in the book.
Do you cover Geo-Scientist and IFoS?
Combined Geo-Scientist Mains Paper I (inorganic chemistry), Paper II (physical chemistry) and Paper III (analytical and organic chemistry) are solved for 2016 to 2025, ten years of each paper. Prelims papers can be downloaded, with solutions planned. Indian Forest Service Chemistry Papers I and II are solved for 2021 to 2025: a full five-question attempt (200 of 320 marks) per paper, with every other part on its own page.
The books
Which books are available, and at what price?
Six Kindle eBooks, ₹599 each: UPSC Civil Services (Main) Chemistry Paper I: Model Answers 2021 to 2025, UPSC Civil Services (Main) Chemistry Paper II: Model Answers 2021 to 2025, UPSC Combined Geo-Scientist (Main) Chemistry Paper I: Model Answers 2021 to 2025, UPSC Combined Geo-Scientist (Main) Chemistry Paper II: Model Answers 2021 to 2025, UPSC Combined Geo-Scientist (Main) Chemistry Paper III: Model Answers 2021 to 2025 and UPSC Indian Forest Service (Main) Chemistry Paper I: Model Answers 2021 to 2025. All six are on Amazon.in.
What is in a book that is not on the site?
Every question of all five papers in one volume, with the question printed above its answer, the full syllabus, topic-wise weightage, a topic-wise index and a question choice and time plan for each paper.
Can I see sample pages before buying?
Yes. Each book page on this site has sample pages to read, and Amazon lets you send yourself a free Kindle sample.
How do I read the books?
They are Kindle eBooks with fixed pages, so every diagram stays where it was drawn. Read them in the free Kindle app on a phone, tablet or computer. Some older e-ink Kindle devices do not open fixed-page books, so check the supported devices on the Amazon page or try the free sample first.
Is there a printed copy?
Yes. Each book can be ordered from its page here as a spiral-bound printed copy on A4, posted anywhere in India within 3 working days, with delivery included. The Kindle edition stays on Amazon.
Using the site
Are the solutions free?
Yes. The model answers can be read on this site page by page, with no account. They are not offered as a download.
Can I download the question papers?
Yes. Every question paper listed here can be read on the site and downloaded as a PDF.
Is there a test series?
Yes. Mains tests for Civil Services, IFoS and Geo-Scientist: you write a full paper by hand, upload your copy on this website, and get it back checked with marks and comments on each answer. The first test of each series is free. Geo-Scientist Prelims has its own online MCQ test series.
I think a solution has a mistake. Where do I report it?
Write to [email protected] or post on Telegram with the exam, paper, year and question number. Corrections are announced on Telegram.
Is VKC Science part of UPSC?
No. VKC Science is not affiliated with the Union Public Service Commission. Question papers belong to UPSC; the solutions are original work.
Not answered here? Write to contact, or see exactly which papers are solved on the coverage page.