Cracking

Question 1

Long hydrocarbons have high/low boiling point and are thinner/viscous and paler/darker in colour

Answer 1

High
Viscous
Darker

Question 2

Shorter hydrocarbons have high/low boiling point and are thinner/viscous

Answer 2

Low
Thinner
Paler

Question 3

To meet the high demand for short-chain hydrocarbons, the longer hydrocarbons are …….. into ………………… which is called ………..

Answer 3

Split into more useful short-chained molecules called cracking

Question 4

Cracking -

Answer 4

a form of thermal decomposition, the breakdown on molecules into simpler molecules by heating them
- also produces alkenes, used to make polymers

Question 5

What are conditions needed for cracking

Answer 5

Heat and Catalyst
- vapourised hydrocarbons are passed over a powdered catalyst at about 600-700 degrees
- catalysts used : silica (SiO2) or alumin (Al2O3)