JEE Main · 2020 · 07 Jan 2020 · Shift 1 · Redox Reactions and Electrochemistry

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Oxidation number of potassium in , and respectively is
  1. (A)+1, +2 and +4
  2. (B)+2, +1 and +
  3. (C)+1, +1 and +1✓ Correct
  4. (D)+1, +4 and +2

Answer: (C)

Solution

Potassium, an alkali metal, keeps a oxidation state throughout. In oxygen is , in the peroxide each oxygen is , and in the superoxide oxygen is ; in every case charge balance leaves potassium at , so the values are .

JEE Main · 2020 · 07 Jan 2020 · Shift 1 · Single correct option

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