UPSC Combined Geo-Scientist, Mains · 2024 · Mains Paper I
Q4(c). Number of ions in an FeO unit cell
Question
Iron(II) oxide, FeO, crystal has a cubic structure and each edge of the unit cell is 5.0 Å. Taking density of the oxide as 4.0 g cm⁻³, calculate the number of Fe²⁺ and O²⁻ ions present in each unit cell.
Model answer
The free solution for 2024 answers questions 1, 2, 5, 6, 9 and 11, the ones picked in its time plan. Question 4 is answered in full in the Geo-Scientist Chemistry Paper I, 2021 to 2025 book, with every part of every paper.
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UPSC Combined Geo-Scientist (Main) Chemistry Paper I: Model Answers 2021 to 2025
- All eleven questions of each paper, with the question printed above its answer
- Titration, gravimetric and nuclear numericals worked with units; structures drawn
- Topic-wise weightage and a topic-wise index
CoversFeO unit celldensity calculationformula units per cellrock salt structure
All parts of Question 4
- 4(a) Colour of oxy- and deoxyhaemoglobin10 marks
- 4(b) Trans-effect control of platinum isomers10 marks
- 4(c) Number of ions in an FeO unit cell10 marks