Organic chemistry Vu Tuan Tai K55 TT KHMT Cracking alkanes Definition: Break the larger hydrocarbon molecules into smaller and more useful molecules Source: Crude oil For example: C15H32 2C2H4 + C3H6 + C8H18 Pentadecane ethene propene octene Ethene and propene are important materials for making plastics Octane is one of the molecules found in petrol Catalytic cracking Thermal cracking