C9.2 - Fractional distillation of oil

Question 1

There is a great variety of what molecules

Answer 1

There is a great variety of hydrocarbon molecules

Question 2

There is a great variety of hydrocarbon molecules.

What are some?

Answer 2

Some hydrocarbon molecules are quite small

Question 3

There is a great variety of hydrocarbon molecules.
Some hydrocarbon molecules are quite small, with relatively few carbon atoms in short chains.
What do these short-chain molecules make up?

Answer 3

These short-chain molecules make up the hydrocarbons that tend to be most useful

Question 4

There is a great variety of hydrocarbon molecules.
Some hydrocarbon molecules are quite small, with relatively few carbon atoms in short chains.
These short-chain molecules make up the hydrocarbons that tend to be most useful.
Why do these short-chain hydrocarbons make good fuels?

Answer 4

These short-chain hydrocarbons make good fuels, because they:

1. Ignite easily
2. Burn well, with less smoky flames than hydrocarbons made up of larger molecules

Question 5

Short-chain hydrocarbons make good fuels, as they ignite easily and burn well, with less smoky flames than hydrocarbons made up of larger molecules.
What are they described as?

Answer 5

Short-chain hydrocarbons are described as very flammable

Question 6

Flammable

Answer 6

Flammable is:

1. Easily ignited
2. Capable of burning rapidly

Question 7

There is a great variety of hydrocarbon molecules.
Some are quite small, with relatively few carbon atoms in short chains.
These short-chain molecules make up the hydrocarbons that tend to be most useful.
What do other hydrocarbons have?

Answer 7

Other hydrocarbons:

1. Have lots of carbon atoms in their long-chain molecules
2. May have branches (side-chains) or form rings

Question 8

What do the properties of hydrocarbons depend on?

Answer 8

The properties of hydrocarbons depend on the chain length of their molecules

Question 9

Boiling point

Answer 9

Boiling point is the temperature at which the:
1. Liquid boils
Or,
2. Gas condenses

Question 10

Volatility

Answer 10

Volatility is the tendency to turn into a gas

Question 11

Viscosity

Answer 11

Viscosity is how easily it flows

Question 12

Flammability

Answer 12

Flammability is how easily it burns

Question 13

As the size of the molecule increases (long chain), what happens to the boiling point?

Answer 13

As the size of the molecule increases (long chain), the boiling point increases

Question 14

As the size of the molecule increases (long chain), what happens to the volatility?

Answer 14

As the size of the molecule increases (long chain), the volatility decreases

Question 15

As the size of the molecule increases (long chain), what happens to the viscosity?

Answer 15

As the size of the molecule increases (long chain), the viscosity increases

Question 16

As the size of the molecule increases (long chain), what happens to the flammability?

Answer 16

As the size of the molecule increases (long chain), the flammability decreases

Question 17

Low viscosity

Answer 17

Low viscosity means very runny

Question 18

High viscosity

Answer 18

High viscosity means thick

Question 19

Lower flammability

Answer 19

Lower flammability means a smokier flame

Question 20

What is crude oil separated into?

Answer 20

Crude oil is separated into hydrocarbons with similar boiling points, called fractions

Question 21

Crude oil is separated into hydrocarbons with similar boiling points, called fractions.
What is this process called?

Answer 21

This process is called fractional distillation

Question 22

Fractional distillation

Answer 22

Fractional distillation is a way to separate liquids from a mixture of liquids by:

1. Boiling off the substances at different temperatures
2. Then condensing and collecting the liquids

Question 23

Crude oil is separated into hydrocarbons with similar boiling points, called fractions.
This process is called fractional distillation.
What does each hydrocarbon fraction contain?

Answer 23

Each hydrocarbon fraction contains molecules with similar numbers of carbon atoms

Question 24

Crude oil is separated into hydrocarbons with similar boiling points, called fractions.
This process is called fractional distillation.
Each hydrocarbon fraction contains molecules with similar numbers of carbon atoms.
What does each of these fractions do?

Answer 24

Each of these fractions boils at a different temperature range

Question 25

Crude oil is separated into hydrocarbons with similar boiling points, called fractions. This process is called fractional distillation. Each hydrocarbon fraction contains molecules with similar numbers of carbon atoms. Why does each of these fractions boil at a different temperature range?

Answer 25

Each of these fractions boils at a different temperature range, because of the different sizes of the molecules in it

Question 26

What does the boiling point of a hydrocarbon depend on?

Answer 26

The boiling point of a hydrocarbon depends on the size of its molecules

Question 27

The boiling point of a hydrocarbon depends on the size of its molecules. What can be used to separate the hydrocarbons in crude oil into fractions?

Answer 27

Differences in boiling points can be used in fractional distillation to separate the hydrocarbons in crude oil into fractions

Question 28

What happens to the crude oil before it goes into the tower?

Answer 28

The crude oil is vaporised before it goes into the tower

Question 29

The crude oil is vaporised before it goes into the tower. | What is at the bottom of the tower, at over 350 degrees Celsius, there is what?

Answer 29

At the bottom of the tower, at over 350 degrees Celsius, there is residue

Question 30

At the bottom of the tower, at over 350 degrees Celsius, there is residue. This is a very thick, sticky mixture of long-chain hydrocarbons. What the residue used in?

Answer 30

The residue at the bottom of the tower is used in making: 1. Roads 2. Flat roofs

Question 31

The crude oil is vaporised before it goes into the tower. | What is the 1st fraction?

Answer 31

The 1st fraction is diesel oil/gas oil

Question 32

The crude oil is vaporised before it goes into the tower. The 1st fraction is diesel oil/gas oil. What is diesel oil/gas oil used as?

Answer 32

Diesel oil/gas oil is used as: 1. Fuel in diesel engines 2. Boiler fuel

Question 33

The crude oil is vaporised before it goes into the tower. The 1st fraction is diesel oil/gas oil. What is the 2nd fraction?

Answer 33

The 2nd fraction is kerosene

Question 34

The crude oil is vaporised before it goes into the tower. The 1st fraction is diesel oil/gas oil. The 2nd fraction is kerosene. What is kerosene used for?

Answer 34

Kerosene is used for aircraft fuel

Question 35

The crude oil is vaporised before it goes into the tower. The 1st fraction is diesel oil/gas oil. The 2nd fraction is kerosene. What is the 3rd fraction?

Answer 35

The 3rd fraction is gasoline/petrol

Question 36

``` The crude oil is vaporised before it goes into the tower. The 1st fraction is diesel oil/gas oil. The 2nd fraction is kerosene. The 3rd fraction is gasoline/petrol. What is gasoline/petrol used for? ```

Answer 36

Gasoline/petrol is used for fuel in car engines

Question 37

``` The crude oil is vaporised before it goes into the tower. The 1st fraction is diesel oil/gas oil. The 2nd fraction is kerosene. The 3rd fraction is gasoline/petrol. What is the 4th fraction? ```

Answer 37

The 4th fraction is refinery/petroleum gas (short-chain hydrocarbons and low boiling point alkanes)

Question 38

The crude oil is vaporised before it goes into the tower. The 1st fraction is diesel oil/gas oil. The 2nd fraction is kerosene. The 3rd fraction is gasoline/petrol. The 4th fraction is refinery/petroleum gas (short-chain hydrocarbons and low boiling point alkanes). What is refinery/petroleum gas (short-chain hydrocarbons and low boiling point alkanes) used as?

Answer 38

Refinery/petroleum gas (short-chain hydrocarbons and low boiling point alkanes) is used as fuel

Question 39

The temperature at the 4th fraction of the tower

Answer 39

The temperature at the 4th fraction of the tower is 50 degrees Celsius

Question 40

What is headed and fed in near the bottom of a tall tower (called a fractionating column) as hot vapour?

Answer 40

Crude oil is: 1. Heated 2. Fed in near the bottom of a tall tower (called a fractionating column) as hot vapour

Question 41

Crude oil is heated and fed in near the bottom of a tall tower (called a fractionating column) as hot vapour. How is the column kept?

Answer 41

The column is kept: 1. Very hot at the bottom 2. Much cooler at the top

Question 42

Crude oil is heated and fed in near the bottom of a tall tower (called a fractionating column) as hot vapour. The column is kept very hot at the bottom and much cooler at the top, so the temperature decreases going up the column. What do the gases do?

Answer 42

The gases move up the column

Question 43

Crude oil is heated and fed in near the bottom of a tall tower (called a fractionating column) as hot vapour. The column is kept very hot at the bottom and much cooler at the top, so the temperature decreases going up the column. The gases move up the column and the hydrocarbons condense when they reach the temperature of their boiling points. How are the different fractions collected?

Answer 43

The different fractions are collected as liquids at different levels

Question 44

Hydrocarbons with the smallest molecules have the lowest what?

Answer 44

Hydrocarbons with the smallest molecules have the lowest boiling points

Question 45

Hydrocarbons with the smallest molecules have the lowest boiling points. Where are they piped out?

Answer 45

Hydrocarbons with the smallest molecules are piped out of the cooler top of the column as gases

Question 46

Hydrocarbons with the smallest molecules have the lowest boiling points. They are piped out of the cooler top of the column as gases. At the bottom of the column, the fractions have high what?

Answer 46

At the bottom of the column, the fractions have high boiling points

Question 47

Hydrocarbons with the smallest molecules have the lowest boiling points. They are piped out of the cooler top of the column as gases. At the bottom of the column, the fractions have high boiling points. What do they do?

Answer 47

``` The fractions at the bottom of the column with high boiling points cool to form very thick: 1. Liquids Or, 2. Solids at room temperature ```

Question 48

Once collected from the fractionating column, what do the fractions need before they can be used?

Answer 48

Once collected from the fractionating column, the fractions need more processing before they can be used

Question 49

There is a great variety of hydrocarbon molecules. | Some hydrocarbon molecules are quite small, with what?

Answer 49

Some hydrocarbon molecules are quite small, with relatively few carbon atoms in short chains

Question 50

The crude oil is vaporised before it goes into the tower. At the bottom of the tower, at over 350 degrees Celsius, there is residue. This is what?

Answer 50

This is a very thick, sticky mixture of long-chain hydrocarbons

Question 51

Crude oil is heated and fed in near the bottom of a tall tower (called a fractionating column) as hot vapour. The column is kept very hot at the bottom and much cooler at the top, so what?

Answer 51

The column is kept: 1. Very hot at the bottom 2. Much cooler at the top ,so the temperature decreases going up the column

Question 52

Crude oil is heated and fed in near the bottom of a tall tower (called a fractionating column) as hot vapour. The column is kept very hot at the bottom and much cooler at the top, so the temperature decreases going up the column. The gases move up the column and the hydrocarbons do what?

Answer 52

The: 1. Gases move up the column 2. Hydrocarbons condense when they reach the temperature of their boiling points

Question 53

Crude oil is heated and fed in near the bottom of a tall tower (called a fractionating column) as hot vapour. The column is kept very hot at the bottom and much cooler at the top, so the temperature decreases going up the column. The gases move up the column and the hydrocarbons condense when they reach the temperature of their boiling points. The different fractions are collected as liquids at different levels. How are the fractions collected from the column?

Answer 53

The fractions are collected from the column in a continuous process