Ethanol can be catalytically dehydrated to ethylene. Apart from aluminium oxide, anhydrous aluminium sulphate or aluminium asbestos are also suitable. Potassium permanganate acts as an oxidizing agent in the presence of double bonds. The characteristic colour change from violet to brown results from the formation of manganese hydroxide:
3 C2H4 + 2 KMnO4 + 6 H2O → 3 HO-CH2-CH2-OH + 2 MnO(OH)2 + 2 KOH

The homologous series of the alkenes can be developed just as it was done for the alkanes. The similarities can be demonstrated by means of solubilities, combustibilities, reactivities etc. (e.g. compared to hexene).

Learning objectives

• Ethylene can be prepared by the reduction of ethanol with aluminium oxide.
• Ethylene is an "unsaturated" and therefore relatively reactive hydrocarbon, which belongs to the group of olefins.

Benefits

• Easy teaching and efficient learning by using interactive experimentation PHYWE-Software
• Experiment is part of a complete solution set with experiments for the topic Organic Chemistry matched with international curriculum: all topics are covered