ALCOHOL -------> ALKENE
- In the dehydration of alcohols, a molecule of water is eliminated from each alcohol molecule to produce alkene.
- There are two methods of dehydration:
a) Ethanol vapour is passed over a heated unglazed porcelain chips, porous pot, pumice stone or alumina (aluminium oxide).
b) Ethanol is heated under reflux at 170 °C with excess concentrated sulphuric acid.
School Laboratory Experiment
- Alkene can be tested by decolourising brown bromine water or decolourising purple acidified potassium manganate (VII) solution.