5.13 - I describe the catalytic cracking of long-chain hydrocarbons.

1. A Catalyst is a substance that changes the rate of a reaction without being used up itself.

2. A Catalyst (silica or alumina in this case) is used in the process of catalytic cracking to increase the rate of reaction. This increases the amount of short- chain molecules that one can produce in a shorter amount of time. In turn, this increases the profits of the oil company and produces more useful hydrocarbons more quickly.

3. A high temperature (600 - 700 degrees Celsius) is used during the process of catalytic cracking. This high temperature is necessary because it increases the rate of reaction further and provides additional energy that is used to break the bonds of the long-chain hydrocarbons more effectively. This increases the output of short-chain hydrocarbons and increases the profits of the oil company.