Cracking

Question 1

What is petrol used for?

Answer 1

= vehicles
= raw material

Question 2

What is the problem for crude oil?

Answer 2

= has a higher porportion of long chained hydrocarbons
= less in demand

Question 3

What does cracking do?

Answer 3

= converts longer chained hydrocarbons into shorter chained hydrocarbons
= produces an alkene, hightly reactive

Question 4

Why are alkenes used?

Answer 4

= feedstock
= raw material
= make polymers
=

Question 5

What happens in thermal cracking?

Answer 5

= conditions:
= high pressure + high temperature
= produces mostly alkenes
= sometimes produced hydrogen

Question 6

What happens in catalytic cracking?

Answer 6

= conditions:
= slight + moderate pressure
= high temperature
= zeolite catalyst
= produces branched and cyclic alkanes- used for making motor fuels
= cheaper than thermal cracking- saves energy as lower temperatures and pressures are used

Question 7

What are the economic reasons for cracking?

Answer 7

= shorter chained alkanes are in higher demand for fuels
= makes use of excess hydrocarbons
= products of cracking are more valuable than the starting reactants

Question 8

Why does cracking require a high temperature?

Answer 8

= involves the splitting of strong covalent bonding
= requires high temperaturs