Alkenes undergo electrophilic addition reactions.
They also participate in oxidation, polymerization and some replacement reactions.
Alkens burn in oxygen or air to give carbon dioxide , water and large amount of heat.
Potassium permanganate - cold and hot
Reaction with Ozone
of vinyl chloride
Addition of sulphuric acid
Cold and concentrated sulphuric acid adds to alkenes forming alkyl hydrogen sulphate.
This adds to water to give alcohol. Actually the final reaction is same as acid catalysied hydration of alkenes.