Alkenes are unsaturated hydrocarbons which contain carbon-carbon double bond ( C = C ) . It is a homologous series with the general formula C n H 2 n . Ethene is the first member of the alkene series with the molecular formula C 2 H 4 .

Alcohols are organic compounds that contain a hydroxyl functional group ( - OH ) which bound to a saturated carbon atom. The alcohol series is a homologous series with the general formula C n H 2 n + 1 OH , each member will differ by a - CH 2 group. Methanol is the first member of the alcohol series and ethanol is the second member which is the major component of alcoholic beverages.

Catalysts are substances that cause a chemical reaction to occur and increase the rate of a chemical reaction and does not undergo any permanent chemical change. Nickel, platinum, or palladium is used as a catalyst in the hydrogenation reaction of unsaturated compounds.