C9.4 Cracking hydrocarbons Flashcards
What is cracking?
Process of turning less useful large hydrocarbon molecules into smaller more useful ones
Why crack hydrocarbons?
It helps to match the supply of fractions with the demand for them.
It produces alkenes, which are useful as feedstock for the petrochemical industry
What are crackers?
The process which takes place at an oil refinery in steel vessles
How can you crack hydrocarbons?
Passed over a hot catalyst
Mixed with steam and heated to a very high temperature
How are the hydrocarbons cracked?
As thermal decomposition
What is catalytic cracking?
Catalytic cracking uses a temperature of approximately 550°C and a catalyst known as a zeolite which contains aluminium oxide and silicon oxide
What is steam cracking?
Steam cracking uses a higher temperature of over 800°C and no catalyst
What is the structure of alkenes?
Unsaturated hydrocarbons which contain at least one double carbon bond
Why are alkenes more reactive than alkanes?
Because they can take part in reactions that alkanes cannot due to being unsaturated
What is the formula for alkenes?
CnH2n
How can you test for alkenes?
Adding the solution to orange bromine water
It turns colorless
