Fractional distillation of crude oil

Question 1

What is crude oil

Answer 1

Crude oil is a mixture of many different short and long chain hydrocarbons that can be burned to give energy in many different forms

Question 2

What is a hydrocarbon

Answer 2

A mixture of Carbon molecules and Hydrogen molecules

Question 3

As a mixture, what use does crude oil have

Answer 3

None

Question 4

What types of molecules does crude oil contain

Answer 4

Short-chain

Long-chain

Question 5

What is fractional distillation

Answer 5

Separating the different hydrocarbons of crude oil in a distillation column

Question 6

How are the crude oil hydrocarbons separated

Answer 6

Burned where they condense at different fractions depending on their size and boiling point

Question 7

What is the link between size and boiling point in fractional distillation

Answer 7

The hydrocarbons of similar sizes condense at similar temperatures

Question 8

What are 3 features of the upper part of the column

Answer 8

Hydrocarbons have lower-boiling points
Molecules of the fractions at the top have less carbon atoms therefore are less dense
Hydrocarbons are less viscous

Question 9

What are 3 features of the lower part of the column

Answer 9

Hydrocarbons have higher-boiling points
Molecules of the fractions at the bottom have more carbon atoms and so are more dense
Hydrocarbons are more viscous

Question 10

Explain Fractional distillation of crude oil

Answer 10

1. Crude oil is heated in a furnace at the side of the distillation column
2. The less-dense hydrocarbons with the lowest boiling points become gaseous first and rise to the top of the column where temperatures are cooler
3. The gaseous hydrocarbons from the crude oil condense from Gas to Liquid when the temperature of the column drops to their boiling point
4. The more-dense hydrocarbons with the higher boiling points condense lower in the column where the temperatures are hotter