VKC ScienceChemistry for written exams Telegram

UPSC Combined Geo-Scientist

Chemist

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

Mains Paper III covers analytical and organic chemistry.

UPSC Combined Geo-Scientist, Mains · 2016 · Mains Paper III

Q12(a). Solvent shifts of electronic bands

Question

Explain why polar solvents usually shift π→π* bands to longer wavelength and n→π* bands to shorter wavelength.

Answer in brief

Differential solvation changes the energy gap: commonly it decreases for ππ* and increases for nπ*.

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 2016 solution2016 question paper

CoversSolvent shifts of electronic bandsUV spectroscopy

All parts of Question 12