VKC ScienceChemistry for written exams Telegram

Indian Forest Service (Mains)

Chemistry optional

  • 2 papers
  • 200 marks each
  • 3 h per paper

Paper I covers physical and inorganic chemistry.

Indian Forest Service (Mains), Chemistry optional · 2023 · Paper I

Q7(c). Platinum–alkyne bonding

Question

In [Pt⁰(η²-PhC≡CPh)(PPh₃)₂], the C–C bond length is 1.32 Å and C–C–Ph bond angle is 140°. Write the structure and justify the bonding.

Model answer

The free solution for 2023 answers questions 1, 2, 4, 5 and 6, the ones picked in its time plan. Question 7 is answered in full in the IFoS Chemistry Paper I, 2021 to 2025 book, with every part of every paper.

Read the 2023 solution

Part of VKC Basic

Read the key points and the full model answer with VKC Basic

VKC Basic (₹999 for 6 months) opens every solved answer, the notes, the handbook and the daily answer archive. Every Mains test series includes it.

See what is included Already a member? Sign in

Cover of UPSC Indian Forest Service (Main) Chemistry Paper I: Model Answers 2021 to 2025
Printed copy and Kindle

UPSC Indian Forest Service (Main) Chemistry Paper I: Model Answers 2021 to 2025

  • All eight questions of each paper, with the question printed above its answer
  • Physical chemistry numericals worked with units; inorganic structures drawn
  • Topic-wise weightage and a topic-wise index
Printed copyKindle editionRead sample pages

Topic notes: organometallics: 18-electron rule, oxidative addition, fluxional molecules and Wilkinson's catalyst, with every Civil Services, IFoS and Geo-Scientist PYQ →

CoversDewar–Chatt–Duncanson modelplatinum alkyne complexπ back-bondingmetallacyclopropenediphenylacetylene

All parts of Question 7