Unit 4 - Lesson 6: Crude Oil

Question 1

What is crude oil a mixture of?

Answer 1

Crude oil is a mixture of hydrocarbons.

Question 2

Coal, natural gas and crude oil are all what?

Answer 2

Fossil fuels.

Question 3

What are hydrocarbons made of only?

Answer 3

Carbon and hydrogen.

Question 4

What is crude oil made from? How is it made?

Answer 4

Crude oil is made from living things that died millions of years ago in the sea. They were gradually covered in layers of sediment. Under high pressure and heat, they turned to crude oil.

Question 5

Is crude oil considered renewable or non-renewable? Why?

Answer 5

It’s considered non-renewable because it takes millions of years to remake. Crude oil is finite.

Question 6

What does it mean when I say “crude oil is finite”?

Answer 6

Crude oil is finite (will run out if we keep using it at this rate).

Question 7

What process is used to separate crude oil into useful products in an oil refinery?

Answer 7

Fractional distillation.

Question 8

Crude oil is separated into useful products in an oil refinery using fractional distillation. What do we call these useful products?

Answer 8

Fractions.

Question 9

What do ‘fractions’ (useful products) contain?

Answer 9

Hydrocarbon chains of similar length.

Question 10

What are fractions separated in?

Answer 10

A fractionating column.

Question 11

When defining a hydrocarbon in your exam, what word should you make sure to write before ‘carbon and hydrogen’?

Answer 11

Hydrocarbons are made of ONLY carbon and hydrogen.

Question 12

What are refinery gases often used as?

Answer 12

Liquified petroleum gas (LPG).

Question 13

What is LPG used for?

Answer 13

LPG is used for heating homes and cooking.

Question 14

What is LPG a mixture of?

Answer 14

Methane, ethane, propane and butane.

Question 15

Can refinery gases be separated into these products (methane, ethane, propane and butane) if needed?

Answer 15

Yes.

Question 16

Draw a fractionating column that begins with refinery gases and ends with bitumen. Label what each gas is used for and give the temperatures for the beginning and ending.

Answer 16

https://i.pinimg.com/736x/05/f4/e3/05f4e361aaccef3e6cff65655929835f.jpg

Question 17

What is the mnemonic for a crude oil fractionating column?

Answer 17

Lazy Penguins Keep Drinking Hot Beer.
LPG, Petrol, Kerosene, Diesel, Heavy Fuel Oil, Bitumen.

Question 18

Give the uses of these gases/fuels:
(a) LPG
(b) Petrol/Gasoline
(c) Kerosene
(d) Diesel
(e) Heavy Fuel Oil
(f) Bitumen

Answer 18

(a) Heating homes & cooking
(b) Fuel for cars
(c) Aircraft fuel
(d) Fuel for cars, lorries & buses
(e) Fuel for ships and power stations
(f) Bitumen for roads & roofs

Question 19

What temperature is the bottom of the fractionating column for crude oil?

Answer 19

400 Degrees Celsius.

Question 20

What temperature is the top of the fractionating column for crude oil?

Answer 20

25 Degrees Celsius.

Question 21

Are the crude oils at the bottom of the fractionating column large or small molecules? What properties do they share?

Answer 21

They’re large molecules.
- High boiling points
- Not very volatile
- Doesn’t flow easily
- Doesn’t ignite easily

Question 22

Are the crude oils at the top of the fractionating column large or small molecules? What properties do they share?

Answer 22

They’re small molecules.
- Low boiling points
- Very volatile
- Flows easily
- Ignites easily

Question 23

Before entering the fractionating column, (WHAT) is done to the crude oil until the majority is turned into a (WHAT)?

Answer 23

Before entering the fractionating column, the crude oil is HEATED until the majority is turned into a VAPOUR.

Question 24

Which end of the column is cooler? Is there a temperature gradient?

Answer 24

The top.
There is a temperature gradient; the top of the column is cooler than the bottom.

Question 25

What happens to the gas as it rises?

Answer 25

It cools and condenses when it reaches a temperature just below its boiling point.

Question 26

Through (WHAT) does the liquid fraction pour out of the column?

Answer 26

Through a CONDENSER, the liquid fraction pours out of the column (is separated).

Question 27

Do short hydrocarbons have lower or higher boiling points than long hydrocarbons?

Answer 27

Short hydrocarbons have lower boiling points than long hydrocarbons.

Question 28

Short hydrocarbons have lower boiling points than long hydrocarbons. Do they condense higher up or lower down the column?

Answer 28

They condense higher up the column.

Question 29

The boiling point is also the (WHAT) point for crude oils?

Answer 29

The boiling point is also the CONDENSATION point.

Question 30

What state do refinery gases stay in and why?

Answer 30

Refinery gases stay in a gas state because the temperature never gets low enough to condense.

Question 31

Why does bitumen never turn to gas?

Answer 31

Bitumen has such a high boiling point that it never turns to gas. It's the crude oil that couldn't be vaporised. It pours out the bottom of the column.

Question 32

Explain how the fractional distillation of crude oil works.

Answer 32

Before entering the column, the crude oil is HEATED until the majority is turned into a VAPOUR. The TOP OF THE COLUMN IS COOLER THAN THE BOTTOM. We say there's a temperature gradient. As the gas rises, it cools, and CONDENSES when it reaches a temperature just below its boiling point. The LIQUID fraction pours out of the column (is separated) through a CONDENSER. Short hydrocarbons have LOWER BOILING POINTS than long, so they CONDENSE HIGHER UP THE COLUMN. The BOILING POINT is also the CONDENSATION POINT. Refinery gases stay in a gas state because the temperature never gets low enough to condense. Bitumen has such a high boiling point that it never gets turned to gas. It's the crude oil that couldn't be vaporised. It pours out the bottom of the column.

Question 33

Fractions at the top of the column are SMALLER or BIGGER hydrocarbon chains?

Answer 33

Fractions at the top of the column are SMALLER hydrocarbon chains.

Question 34

What are hydrocarbons? So, if you burn them, what do they release?

Answer 34

Fuels, so if you burn them, they release heat energy.

Question 35

Do smaller hydrocarbons burn easier? Why or why not? What do we say smaller hydrocarbons are more due to this?

Answer 35

Yes, smaller hydrocarbons burn easier because the INTERMOLECULAR FORCES between molecules are weaker. We say they are more COMBUSTIBLE.

Question 36

(Short/Long) molecules have (stronger/weaker) intermolecular forces. (More/Less) energy is required to break them. (Short/Long) molecules have (stronger/weaker) intermolecular forces. (More/Less) energy is required to break them.

Answer 36

SHORT molecules have WEAKER intermolecular forces. LESS energy is required to break them. LONG molecules have STRONGER intermolecular forces. MORE energy is required to break them.

Question 37

Are shorter fractions more or less volatile?

Answer 37

Shorter fractions are MORE volatile.

Question 38

Do shorter fractions evaporate easily or not?

Answer 38

Shorter fractions evaporate easily.

Question 39

What colour and texture is crude oil? How does the colour and texture of crude oil change?

Answer 39

It's black and viscous (tar-like). As the hydrocarbon chain of a fraction gets shorter, its colour gets lighter and viscosity decreases.

Question 40

Finish these sentences: (a) The shorter the chain length, the (MORE/LESS) combustible. (b) The lower the boiling point, the (MORE/LESS) volatile (how easy it turns to vapour). (c) The chain length (INCREASES/DECREASES) lower in the fractionating column. (d) The colour gets (LIGHTER/DARKER) lower in the fractionating column. (e) The boiling point (DECREASES/INCREASES) lower in the fractionating column. (f) The viscosity (DECREASES/INCREASES) lower in the fractionating column.

Answer 40

(a) The shorter the chain length, the MORE combustible. (b) The lower the boiling point, the MORE volatile. (c) The chain length INCREASES lower in the fractionating column. (d) The colour gets DARKER lower in the fractionating column. (e) The boiling point INCREASES lower in the fractionating column. (f) The viscosity INCREASES lower in the fractionating column.

Question 41

Draw a diagram for distilling crude oil. Include the labels: Gasoline (petrol), Naphtha, Kerosene, Diesel Oil, Fuel Oil, and Bitumen Residue. Include the properties of the crude oils at either end of the fractionating column.

Answer 41

https://i.pinimg.com/736x/83/f4/ab/83f4ab37a158e0a729162e8fd073685a.jpg