Fractional Distilation

Question 1

What is fractional distillation

Answer 1

Fractional distillation is when crude oil is separated in to fractions, depending on the length of the molecule

Question 2

Mnemonic for fractional distillation

Answer 2

Good (gases) 
People (petrol)
Never (naphtha) 
Kill (kerosene) 
Dear (diesel) 
Fluffy (fuel oil) 
Bunnies (bitumen)

Question 3

What happens as you go down the fractional column (from big molecules to small)

Answer 3

The big molecules have: 
High boiling point 
Doesn't ignite easily
Viscosity - thick and sticky 
Not volatile (doesn't evaporate easily) 

The smaller molecules have: 
Low boiling point 
Ignites easily 
Viscosity - very runny 
Volatile (evaporates easily at room temperature)

Question 4

What is a hydrocarbon

Answer 4

A compound that contains carbon and hydrogen only

Question 5

What is an alkane

Answer 5

An alkane is a fully saturated hydrocarbon, that contains no double bonds

Question 6

What is an alkene

Answer 6

It is an unsaturated hydrocarbon which contains at least one carbon to carbon double bond

Question 7

What is cracking

Answer 7

Cracking is a reaction in which larger alkanes are decomposed to form shorter alkanes and alkenes

Question 8

Why is cracking useful

Answer 8

The smaller molecules are more in demand, as they are more useful than longer molecules

Question 9

What conditions are required for cracking

Answer 9

A high temperature and a catalyst are needed for cracking