Checklist C9, C10, C11 - Organic Chemistry

Question 1

What is crude oil?

Answer 1

A mixture of hydrocarbons

Question 2

What is crude oil formed from?

Answer 2

The remains of ancient biomass (mostly plankton) that was buried in mud

Question 3

What is a finite resource?

Answer 3

One that will run out

Question 4

Why is crude oil a finite resource?

Answer 4

It takes longer to form than the rate at which we are using it up

Question 5

What is a hydrocarbon?

Answer 5

A compound made up of carbon and hydrogen only

Question 6

What is a general formula?

Answer 6

A mathematical formula which allows you to work out the chemical formula of a substance

Question 7

What is an alkane?

Answer 7

A hydrocarbon with only single bonds

Question 8

Name the first four alkanes.

Answer 8

Methane, ethane, propane, butane

Question 9

What is the general formula for alkanes?

Answer 9

CnH2n+2

Question 10

How does the boiling point change with the length of an alkane?

Answer 10

The longer the alkane the higher the boiling point

Question 11

How does the viscosity change with the length of an alkane?

Answer 11

The longer the alkanes, the more viscous (thicker) it is

Question 12

How does the flammability change with the length of an alkane?

Answer 12

The shorter the alkane, the more flammable it is

Question 13

What is fractional distillation?

Answer 13

A process used to separate mixtures of substances with different boiling points

Question 14

What are the steps involved in fractional distillation?

Answer 14

Crude oil is vapourised.
The column is hotter at the bottom and cooler at the top.
The molecules travel up the column and condense at different points depending on their boiling points. Smaller molecules condense at the top, larger molecules at the bottom.

Question 15

Why is fractional distillation important?

Answer 15

The different fractions have different uses

Question 16

What is a fuel?

Answer 16

A substance which when reacted with oxygen releases energy

Question 17

Name fuels we obtain from crude oil.

Answer 17

Petrol, diesel, kerosene, heavy fuel oil, liquid petroleum gases

Question 18

What other uses are there for products of fractional distillation?

Answer 18

Solvents, lubricants, polymers and detergents

Question 19

What is combustion?

Answer 19

The reaction of a fuel with oxygen

Question 20

What are the products of complete combustion?

Answer 20

Carbon dioxide and water

Question 21

When does incomplete combustion occur?

Answer 21

When there is not enough oxygen present

Question 22

What is cracking?

Answer 22

The process of breaking down long hydrocarbons into smaller ones.

Question 23

What are the products of cracking?

Answer 23

Short alkanes and alkenes

Question 24

Why is cracking important?

Answer 24

Smaller hydrocarbons are more useful than longer ones

Question 25

What are the two types of cracking?

Answer 25

Catalytic and steam cracking

Question 26

What are alkenes?

Answer 26

A type of hydrocarbon with a C=C double bond that is more useful than an alkane

Question 27

What are alkenes used for?

Answer 27

As a starting material to make more useful chemicals

Question 28

How do you test for an alkene?

Answer 28

React it with bromine water

Question 29

What is the colour change when an alkene reacts with bromine water?

Answer 29

Turns from orange to colourless

Question 30

What is the general formula for alkenes?

Answer 30

CnH2n

Question 31

What does unsaturated mean?

Answer 31

Contains double bonds

Question 32

What are the first four alkenes?

Answer 32

Ethene, propene, butene, pentene

Question 33

What are the four reactions of alkenes?

Answer 33

Combustion, with water, with hydrogen, with halogens

Question 34

How is the combustion of alkenes different to the combustion of alkanes?

Answer 34

Alkenes usually burn by incomplete combustion so burn with a smoky flame

Question 35

Why are the reactions of alkenes with hydrogen, water and halogens known as ‘addition reactions’?

Answer 35

Because new atoms are being added to the molecule by breaking the double bond

Question 36

What is the product from the reaction of an alkene with hydrogen?

Answer 36

An alkane

Question 37

What conditions are necessary in the reaction of alkenes with hydrogen?

Answer 37

Nickel catalyst, 60°C

Question 38

What is the product from the reaction of an alkene with a halogen?

Answer 38

An alkane with two halogen atoms where the double bond used to be

Question 39

What is the product of the reaction of an alkene with steam?

Answer 39

An alcohol

Question 40

What conditions are necessary for the reaction of alkenes with steam?

Answer 40

High temperature, high pressure, catalyst

Question 41

What is polymerisation?

Answer 41

The process of using small molecules (monomers) to make long chain molecules (polymers)

Question 42

What monomers are involved in addition polymers?

Answer 42

Alkenes

Question 43

What do the properties of polymers depend on?

Answer 43

The monomers they are made of and the conditions under which they are made

Question 44

What is the difference between thermosetting and thermosoftening polymers?

Answer 44

Thermosoftening ones melt when they are heated, thermosetting do not

Question 45

Why do thermosetting polymers not melt when heated?

Answer 45

They have strong cross-links between the polymer chains

Question 46

Explain what a homologous series is.

Answer 46

A family of hydrocarbons with similar chemical properties.

Question 47

Describe what a fraction is and state the uses of fractions.

Answer 47

Each fraction consists of a group of hydrocarbons of similar chain lengths.
Fractions can be used as fuels. Each fraction has different properties due to the length of the carbon chain. Therefore, we can use each fraction for different purposes.