Cracking (C1)

Fuels made from oil mixtures containg large hydrocarbons are not efficient because they do not ignite or flow easily. Cracking allows large hydrocarbons to be broken down into smaller more useful hydrocarbon molecules. Fractions containing large hydrocarbon molecules are vapourised and passed over a hot catalyst. This breaks the intermolecular forces in the molecules forming smaller more useful hydrocarbons. Whenever we crack a chain we get an ALKANE and an ALKENE.

The test for an ALKENE (double bond) is…