1) Alkenes 
A group of hydrocarbons with general formula C[n]H[2n] .They are also known as Alkenes and include ethylene, C[2]H[4] and propylene, C[3]H[6].
Basic chemicals made from oil or natural gas liquids feed stocks; commonly used to manufacture plastics and gasoline. Examples are ethylene and propylene.
A group of unsaturated hydrocarbons of the general formula CnH2n, and named after the corresponding paraffins by the addition of 'ene' or 'ylene' to the stem.
A group of petrochemicals characterized by their straight or branched structure. Includes ethylene, the largest volume petrochemical, and propylene and butadiene.
A group of chemicals characterized by their straight or branched structure. Includes ethylene, the largest volume petrochemical, and butadiene and propylene.