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AIIMS2018Chemistryd and f Block Elements

In acidic medium, which of the following becomes colourless?

Options

  1. AMnO ₄⁻
  2. BMnO ₄²⁻
  3. CCrO ₄²⁻
  4. DFeO ₄²⁻

Correct answer

A. MnO ₄⁻

Step-by-step solution

MnO ₄⁻ changes from purple to colourless in acidic solution while MnO ₄²⁻ is stable in acidic medium. Yellow coloured CrO ₄²⁻ changes to orange coloured Cr ₂ O ₇²⁻ on acidifying and FeO ₄²⁻ decomposes.

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