A. acidified K2Cr2O7 solution colourless
B. acidified KMnO4 solution colourless
C. Fe(NO3)2 solution green
D. Pb(NO3)2 paper black

Correct Answer:

Option B – acidified KMnO4 solution colourless

Explanation

If the potassium manganate(VII) solution is acidified with dilute sulfuric acid, the purple solution becomes colourless.

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