UPSC Combined Geo-Scientist
Chemist
- 3 descriptive papers
- 200 marks each
- 3 h per paper
Mains Paper I covers inorganic chemistry.
All years
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Mains Paper I, inorganic chemistry
Solution, 2026
UPSC Combined Geo-Scientist, Stage II (Mains). 26 pages. Questions 1, 3, 4, 6, 9 and 10 are answered.
Every question of 2026, one page each39 parts in 11 questions, with the question as text and the key points of its answer
Question 1 50 marks
- 1(a)Zinc blende and wurtzite: radius-ratio rationale5 marks
- 1(b)Spin-forbidden bands in 4d and 5d complexes5 marks
- 1(c)Phosphate buffer at pH 7.405 marks
- 1(d)Onset of AgCl precipitation5 marks
- 1(e)Iodometry and iodimetry5 marks
- 1(f)Masking agents in the estimation of Ca²⁺5 marks
- 1(g)First-row metal in EAN-obeying organometallics5 marks
- 1(h)Radioactive displacement: ²¹⁰Pb and ²²⁶Ra5 marks
- 1(i)Electronic spectra of Eu³⁺ and Am³⁺ complexes5 marks
- 1(j)Urea required to precipitate Fe³⁺ as Fe(OH)₃5 marks
Question 2 30 marks
Question 3 30 marks
Question 4 30 marks
Question 5 30 marks
Question 6 30 marks
Question 7 30 marks
Question 8 30 marks
Question 9 30 marks
Question 10 30 marks