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.