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In the redox reaction: a MnO4⁻ + b I⁻ + c H⁺ -> d Mn²+ + e I2 + f H2O (balanced), find the value of c/d.
- 1.3
- 1.2
- 8
- 5
Correct answer: 8
Solution
Balancing in acid: Reduction half: MnO4⁻ + 8H+ + 5e⁻ -> Mn²+ + 4H2O. Oxidation half: 2I⁻ -> I2 + 2e⁻. Multiply reduction by 2 and oxidation by 5 to equalize electrons (10e each). Overall: 2MnO4⁻ + 16H+ + 10I⁻ -> 2Mn²+ + 5I2 + 8H2O. So a=2, b=10, c=16, d=2, e=5, f=8. c/d = 16/2 = 8.
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