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NTA Abhyas JEE Main2020Chemistryd and f Block ElementsPractice

Pick out the incorrect statement

Options

  1. AM n O 2 dissolves in conc. HCl, but does not form M n 4 + ions
  2. BM n O 2 oxidizes hot concentrated H 2 S O 4 liberating oxygen
  3. CK 2 M n O 4 is formed, when M n O 2 is fused KOH is oxidized by air, K N O 3 , P b O 2 or N a B i O 3
  4. DDecomposition of acidic K M n O 4 is not catalysed by sunlight

Correct answer

D. Decomposition of acidic K M n O 4 is not catalysed by sunlight

Step-by-step solution

Decomposition of acidic K M n O 4 is catalysed by sunlight. 4 M n O 4 - + 4 H + → 4 M n O 2 + 3 O 2 + 2 H 2 O A. On dissolution, MnO 2 forms M n 2 + ions and HCl is oxidized to C l 2 . M n O 2 + 4 HC l - → M n 2 + + 2 C l - + C l 2 + H 2 O B. H 2 S O 4 is oxidized by M n O 2 2 M n O 2 + 2 H 2 S O 4 → 2 M n S O 4 + O 2 + 2 H 2 O C. M n O 2 + 2 K O H + 1 2 O 2 → K 2 M n O 4 G r e e n + H 2 O

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