C9 - Crude Oil

Question 1

What is crude oil?(2)

Answer 1

• Finite resource found in rocks
• Mixture of large number of compounds mostly hydrocarbons

Question 2

What is a hydrocarbon?

Answer 2

Compound of hydrogen and carbon atoms only

Question 3

What is the alkane with 1 carbon atom?

Answer 3

Methane

Question 4

What is the alkane with 2 alkane atoms?

Answer 4

Ethane

Question 5

What is the alkane with 3 alkane atoms?

Answer 5

Propane

Question 6

What is the alkane with 4 alkane atoms?

Answer 6

Butane

Question 7

How can the hydrocarbons in crude oil be separated?

Answer 7

Fractional distillation

Question 8

What uses are there for the fractions of crude oil(2)

Answer 8

Fuels and the petrochemical industry

Question 9

What fuels are produced from crude oil?(5)

Answer 9

• Petrol
• Diesel
• Kerosene
• Heavy fuel oil
• Liquefied petroleum gases

Question 10

What materials are produced by the petrochemical industry?(4)

Answer 10

• Solvents
• Lubricants
• Polymers
• Detergents

Question 11

Why are there lots of natural and synthetic carbon compounds?

Answer 11

Ability of carbon atoms to form families of similar compounds

Question 12

What happens during fractional distillation?(3)

Answer 12

1. Crude oil is heated and evaporates
2. As the gas rises it cools
3. Condenses at its boiling point where it can then be collected

Question 13

What 3 properties of a hydrocarbon depend on its size?

Answer 13

• Boiling point
• Viscosity
• Flammability

Question 14

What happens to the flammability of a hydrocarbon as it becomes bigger?

Answer 14

Decreases

Question 15

What happens to the viscosity of a hydrocarbon as it becomes bigger?

Answer 15

Increases

Question 16

What happens to the melting and boiling point of a hydrocarbon as it becomes bigger?

Answer 16

Increases

Question 17

What happens during combustion of hydrocarbon fuels?(3)

Answer 17

• Carbon and hydrogen in the fuels are oxidised
• Make Carbon dioxide and water
• Release energy

Question 18

What is the word equation for combustion of a fuel from crude oil?

Answer 18

Hydrocarbon + Oxygen –> Carbon dioxide + Water

Question 19

How can hydrocarbons be broken down into smaller molecules?

Answer 19

Cracking

Question 20

What happens during catalyctic cracking?(2)

Answer 20

• Crude oil is vaporised
• Passed over a hot catalyst

Question 21

What happens during steam cracking?

Answer 21

• Crude oil is vaporised
• Mixed with steam
• Heated to a high temperature

Question 22

What are the products of cracking?

Answer 22

Smaller useful alkanes and alkenes

Question 23

How do we test for alkenes?

Answer 23

Add bromine water and if the colour changes to clear then alkene is present

Question 24

What colour change happens when alkenes react with bromine?

Answer 24

Orange to colourless

Question 25

What are alkenes used for?(2)

Answer 25

- Produce polymers - Starting materials for production of many other chemicals

Question 26

Compare cracking and distillation?

Answer 26

- Cracking involves a catalyst, distillation does not - Cracking involves a chemical change, distillation does not

Question 27

Describe what happens when an alkane burns(2)

Answer 27

- Combines with oxygen to make carbon dioxide and water - Reaction as exothermic so releases energy

Question 28

Describe how crude oil is formed

Answer 28

Biomass like plankton is buried in mud and compressed over a long period of time

Question 29

Describe and explain the trend in the boiling points of the alkanes(3)

Answer 29

- The bigger the alkane the higher the boiling point - As molecules get bigger, intermolecular forces between molecules incease - Takes more energy for these to be overocme when alkane turns into a gas

Question 30

Explain why cracking is used in the fuel industry(4)

Answer 30

- Large hydrocarbons are not useful as they do not ignite easily, are not volatile and do not easily flow - Get more useful smaller molecules that can be used as fuels through cracking - Ideal properties for a fuel, volatile, flow, ignite - Alkenes also produced - useful to make polymers