VKC ScienceChemistry for written exams Telegram

UPSC Civil Services (Mains)

Chemistry optional

  • 2 papers
  • 250 marks each
  • 3 h per paper
  • 5 of 8 questions, Q1 and Q5 compulsory

Paper I covers physical and inorganic chemistry.

UPSC Civil Services (Mains), Chemistry optional · 2024 · Paper I

Q8(b)(ii). Structure and bonding of B₂H₆

Question

Draw the structure of B₂H₆. Explain the bonding in B₂H₆ on the basis of the hybridization approach.

Answer in brief

B₂H₆ has two BH₂ groups joined by two B–H–B bridges; each boron is sp³ hybridised, the four terminal B–H bonds are two-electron bonds and each bridge is a three-centre two-electron bond.

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

The full model answer

As written for the answer booklet: the diagram carries the working, the lines stay short. Read here only; it is not offered as a download.

The handwritten model answer pages open with the VKC plan.
Read the whole 2024 solution2024 question paper

Topic notes: main group chemistry: boranes, borazine, phosphazenes, silicates, silicones, interhalogens, xenon and sulfur–nitrogen compounds, with every Civil Services, IFoS and Geo-Scientist PYQ →

Coversdiboranethree-centre two-electron bondbanana bondelectron-deficient compoundssp³ hybridisation

All parts of Question 8