org06 Test for ethylen with potassium permanganate
 The ethylen gas of the previous experiments is sufficient for 3 experiments: Testing with bromine water, burning, testing with potassium permanaganate. For the third experiment transfer 6 ml ethylen into a Liquemin bottle.
Photo 1 and 2: From a syringe add 1.5 ml diluted potassium permanganate solution to the bottle with ethylen, shake.
Photo 3 and 4: Add another 1.5 ml pink potassium permanganate solution, shake.
Observation
The pink colour disappears during mixing (Photo 2).
The pink colour disappears again. This time a brown solid is formed (Photo 4).
Explanation
Ethylen (CH₂=CH₂) is oxidized by permanganate. The alcohol ethane-diole HO-CH₂-CH₂-OH is formed, while permanganate ions are reduced leaving colourless  manganese ions Mn²⁺(aq).
Explanation to photos 3 and 4: The second sample of ethylen was only sufficient to reduce potassium permanganate to the stage of insoluble manganese dioxide MnO₂(s).

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