“Decolorization“ from the “Chemistry of plants“ set
Channel: MEL Chemistry
Date: 19/04/2018

Perform this amazing experiment at home with MEL Science: https://melscience.com/en/experiments/plants-anthocyanin-bleaching/

Safety
* Put on protective gloves and eyewear.
* Conduct the experiment on the plastic tray and in a well-ventilated area.

Disposal
* Dispose of solid waste together with household garbage.
* Pour solutions down the sink.
* Wash with an excess of water.

Step-by-step instructions
1. Anthocyanins are substances which give many flowers their colors, ranging from red to blue.
2. Sodium pyrosulfite Na₂S₂O₅ decomposes in acidic solutions, giving off sulfur dioxide gas—SO₂.
3. Anthocyanins react with SO₂ and lose their color, making the petal’s color fade. The speed of this reaction depends on the petal chosen—the more intense the color, the more time needed.
4. Wash the Petri dish to repeat the experiment.