Organic chemistry deals with carbon compounds, especially hydrocarbons which contain only carbon and hydrogen. Alkenes are unsaturated hydrocarbons containing a carbon-carbon double bond. They can be produced through the dehydration of alcohols, which removes a water molecule, or through the dehydrohalogenation of alkyl halides, which involves heating the alkyl halide with an alcoholic solution of potassium hydroxide to eliminate hydrogen halide and form an alkene.