Fractional distillation of crude oil

Question 1

Why is crude oil called a fossil fuel?

Answer 1

It was formed millions of years ago by the breakdown of plant and animal remains at high pressure and temperatures deep below the Earth’s surface.

Question 2

Is crude oil renewable or nonrenewable?

Answer 2

Non-renewable because it forms very slowly

Question 3

Why does crude oil contain other compounds dissolved in it?

Answer 3

They come from the elements of the original plants and animals the oil was formed from.

Question 4

Some crude oil contains sulfur. What do they produce when they are burnt?

Answer 4

Sulfur dioxide (SO2)

Question 5

What does high level of sulfur dioxide in the environment cause?

Answer 5

Acid rain

Question 6

How does acid rain form?

Answer 6

sulfur dioxide reacts with oxygen high in the atmosphere to form sulfur trioxide. This then reacts with the water in the atmosphere to form sulfuric acid.

Question 7

How do you separate crude oil?

Answer 7

Through fractional distillation

Question 8

Where is fractional distillation done?

Answer 8

In a fractionating tower

Question 9

What are the 4 steps to fractional distillation?

Answer 9

The crude oil is heated in a furnace.
A mixture of liquid and vapour passes into a tower that is cooler at the top than at the bottom.
The vapours pass up the tower via a series of trays, until they arrive at a tray that is at a lower temperature than there boiling point. Then they condense to a liquid.
The liquids on the trays are then piped off.

Question 10

Where do shorter chain hydrocarbons condense in a fractional distillation chamber?

Answer 10

At the top, where it is cooler because they have lower boiling points.

Question 11

Where do longer chain hydrocarbons condense in a fractional distillation chamber?

Answer 11

Near the bottom, where it is warmer because they have higher boiling points.

Question 12

What is the name of the thick residue that is left at the base of the tower?

Answer 12

tar or bitumen

Question 13

What can tar of bitumen be used for?

Answer 13

Road surfacing or for braking down into more useful products.

Question 14

What forces are broken during vaporisation of crude oil

Answer 14

The van der Waals forces between the molecules

Question 15

Why do the hydrocarbon chains themselves not split and vaporise during fractional distillation?

Answer 15

Because fractional distillation is a physical process so no covalent bonds within the molecules are broken

Question 16

Why would people be against fracking as a way of gaining gas supplies?

Answer 16

Increased traffic
They are concerned about the amount of water used
The worry about the chemical additives polluting water supplies
Occasionally fracking appears to have caused small earthquakes
It produces carbon dioxide which contributes to global warming