UPSC Combined Geo-Scientist, Mains · 2016 · Mains Paper I
Q9(b). Dichromate half-reaction
Question
Balance the following ionic reaction by ‘ion electron’ method in acidic medium: Cr₂O₇²⁻ → Cr³⁺.
Answer in brief
Cr₂O₇²⁻ + 14H⁺ + 6e⁻ → 2Cr³⁺ + 7H₂O.
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CoversDichromate half-reactionIon–electron balancing
All parts of Question 9
- 9(a) Classification of silicates15 marks
- 9(b) Dichromate half-reaction7 marks
- 9(c) Oxidation of iodide by dichromate8 marks