Cracking

Question 1

What are the properties of Long Hydrocarbons

Answer 1

They have high boiling points and are viscours

Question 2

What are the properties of Short Hydrocarbons

Answer 2

They have low boiling points and are thin and pale

Question 3

Is demand higher for short-chain or long-chain hydrocarbons?

Answer 3

Demand is higher for short chain hydrocarbons, such as octane which is used in petrol

Question 4

To meet the demand for short chain hydrocarbons what do we do?

Answer 4

We split long chain hydrocarbons into short chain hydrocarbons by cracking

Question 5

What is Cracking a form of? Explain your answer

Answer 5

Cracking is a form of Thermal Decomposition, which means breaking molecules into simpler molecules by heating them

Question 6

What does cracking also produce?

Answer 6

Alkenes, which are used to make polymers

Question 7

Explain the conditions of cracking in industry

Answer 7

In industry, vaporised hydrocarbons are passed over a powdered catalyst at about 600-700 degrees celcius

Question 8

Name the 2 types of powdered catalysts which can be used

Answer 8

Siliaca (SlO2) or Alumina (Al2O3)

Question 9

Explain the cracking process with an alkane

Answer 9

The alkane is heated until vaporised, it then breaks down when it comes into contact with the powdered catalyst, producing a mixture of short chain alkanes and alkenes