Cracking Of Crude Oil

Question 1

What is the process of cracking hydrocarbons?

Answer 1

> thermal decomposition

> 1.) long chain hydrocarbon is heated to evaporate it.

> 2.) vapour is passed over a powdered catalyst at 400-700 degrees Celsius

> 3.) the hydrocarbon splits on the surface of the catalyst

> 4.) products are mostly alkanes and alkenes

Question 2

What is the catalyst for cracking of hydrocarbons?

Answer 2

Powdered Al2O3

Question 3

What are alkenes?

Answer 3

> hydrocarbons which have a double bond between two of the carbon atoms in their chain.

Question 4

Why are alkenes describe as unsaturated?

Answer 4

> because they can make more bonds

- double bond can open up, allowing the carbon atoms to bond with other atoms.

Question 5

What is the general formula for alkenes?

Answer 5

> CnH2n

Question 6

How can you test for alkenes?

Answer 6

> add to bromine water,

> alkenes will decolourise it as the carbon double bond will open up and form bonds with the bromine

Question 7

Why are long chain hydrocarbons cracked?

Answer 7

> because they are not very useful

> can be turned into more useful short chain molecules like paraffin, petrol and ethene