UPSC Combined Geo-Scientist, Mains · 2024 · Mains Paper I
Q3(c). Carbonate–bicarbonate mixtures
Question
Give the salient features of estimation of sodium carbonate and bicarbonate mixtures by acidimetry. Which two acid-base indicators are used and why?
Model answer
The free solution for 2024 answers questions 1, 2, 5, 6, 9 and 11, the ones picked in its time plan. Question 3 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
CoversNa2CO3 NaHCO3 mixturedouble indicator titrationphenolphthaleinmethyl orangeacidimetry
All parts of Question 3
- 3(a) Reading a weak-acid titration curve15 marks
- 3(b) Criteria for a suitable indicator5 marks
- 3(c) Carbonate–bicarbonate mixtures10 marks