UPSC Combined Geo-Scientist, Mains · 2019 · Mains Paper III
Q3(c). Identifying and balancing redox
Question
Identify the redox reaction: (i) BaCl₂ + H₂SO₄ → BaSO₄ + 2HCl; (ii) ClO₃⁻ + Zn + H⁺ → Cl⁻ + Zn²⁺ + H₂O. Balance and identify agents.
Answer in brief
Only (ii) is redox: ClO₃⁻ + 3Zn + 6H⁺ → Cl⁻ + 3Zn²⁺ + 3H₂O.
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CoversIdentifyingbalancing redoxReaction stoichiometry
All parts of Question 3
- 3(a) Potentiometric fluoride measurement10 marks
- 3(b) Isoelectric and isoionic points5 marks
- 3(c) Identifying and balancing redox5 marks
- 3(d) Errors from coprecipitation5 marks
- 3(e) Heavy-metal adsorption on hydrous oxides5 marks