Manganese traffic light
Channel: MEL Chemistry
Date: 24/02/2020

How to make a traffic light from potassium permanganate.

Reagents and equipment: potassium permanganate solution, alkaline glucose solution (glucose solution + drain cleaner), glass.

Mix a potassium permanganate solution with an alkaline glucose solution (glucose solution + drain cleaner). Observe as the solution changes colors like a traffic light.

In an alkaline medium, glucose reduces potassium permanganate, first to potassium manganate, and then to manganese(IV) oxide. In this case, the solution changes colors from raspberry-red to green, then to brown.

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Warning! Only under adult supervision