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 · 2017 · Mains Paper III

Q4(a). Permanganate–chromate mixture

Question

A 0.24 g mixture of KMnO₄ and K₂CrO₄ liberates iodine from acidic KI that requires 60 mL of 0.1 N thiosulfate. Find percentages of Mn and Cr.

Answer in brief

Mn = 20.51%; Cr = 10.98% by mass.

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 2017 solution2017 question paper

CoversPermanganate–chromate mixtureRedox stoichiometry

All parts of Question 4